Chapter3习题集及答案

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公司理财精要版原书第12版习题库答案Ross12e_Chapter03_TB

Fundamentals of Corporate Finance, 12e (Ross)Chapter 3 Working with Financial Statements1) Which one of the following is a source of cash for a tax-exempt firm?A) Increase in accounts receivableB) Increase in depreciationC) Decrease in accounts payableD) Increase in common stockE) Increase in inventory2) Which one of the following is a use of cash?A) Decrease in fixed assetsB) Decrease in inventoryC) Increase in long-term debtD) Decrease in accounts receivablesE) Decrease in accounts payable3) Which one of the following is a source of cash?A) Repurchase of common stockB) Acquisition of debtC) Purchase of inventoryD) Payment to a supplierE) Granting credit to a customer4) Which one of the following is a source of cash?A) Increase in accounts receivableB) Decrease in common stockC) Increase in fixed assetsD) Decrease in accounts payableE) Decrease in inventory5) On the statement of cash flows, which one of the following is considered a financing activity?A) Increase in inventoryB) Decrease in accounts payableC) Increase in net working capitalD) Dividends paidE) Decrease in fixed assets6) On the statement of cash flows, which one of the following is considered an operating activity?A) Increase in net fixed assetsB) Decrease in accounts payableC) Purchase of equipmentD) Dividends paidE) Repayment of long-term debt7) According to the statement of cash flows, an increase in inventory will ________ the cash flow from ________ activities.A) increase; operatingB) decrease; financingC) decrease; operatingD) increase; financingE) increase; investment8) According to the statement of cash flows, an increase in interest expense will ________ the cash flow from ________ activities.A) decrease; operatingB) decrease; financingC) increase; operatingD) increase; financingE) Increase; investment9) Activities of a firm that require the spending of cash are known as:A) sources of cash.B) uses of cash.C) cash collections.D) cash receipts.E) cash on hand.10) The sources and uses of cash over a stated period of time are reflected on the:A) income statement.B) balance sheet.C) tax reconciliation statement.D) statement of cash flows.E) statement of operating position.11) A common-size income statement is an accounting statement that expresses all of a firm's expenses as a percentage of:A) total assets.B) total equity.C) net income.D) taxable income.E) sales.12) Which one of the following standardizes items on the income statement and balance sheet relative to their values as of a chosen point in time?A) Statement of standardizationB) Statement of cash flowsC) Common-base year statementD) Common-size statementE) Base reconciliation statement13) On a common-size balance sheet all accounts for the current year are expressed as a percentage of:A) sales for the period.B) the base year sales.C) total equity for the base year.D) total assets for the current year.E) total assets for the base year.14) On a common-base year financial statement, accounts receivables for the current year will be expressed relative to which one of the following?A) Current year salesB) Current year total assetsC) Base-year salesD) Base-year total assetsE) Base-year accounts receivables15) Which one of the following ratios is a measure of a firm's liquidity?A) Cash coverage ratioB) Profit marginC) Debt-equity ratioD) Quick ratioE) NWC turnover16) An increase in current liabilities will have which one of the following effects, all else held constant? Assume all ratios have positive values.A) Increase in the cash ratioB) Increase in the net working capital to total assets ratioC) Decrease in the quick ratioD) Decrease in the cash coverage ratioE) Increase in the current ratio17) An increase in which one of the following will increase a firm's quick ratio without affecting its cash ratio?A) Accounts payableB) CashC) InventoryD) Accounts receivableE) Fixed assets18) A supplier, who requires payment within 10 days, should be most concerned with which one of the following ratios when granting credit?A) CurrentB) CashC) Debt-equityD) QuickE) Total debt19) A firm has an interval measure of 48. This means that the firm has sufficient liquid assets to do which one of the following?A) Pay all of its debts that are due within the next 48 hoursB) Pay all of its debts that are due within the next 48 daysC) Cover its operating costs for the next 48 hoursD) Cover its operating costs for the next 48 daysE) Meet the demands of its customers for the next 48 hours20) Ratios that measure a firm's liquidity are known as ________ ratios.A) asset managementB) long-term solvencyC) short-term solvencyD) profitabilityE) book value21) Which one of the following statements is correct?A) If the total debt ratio is greater than .50, then the debt-equity ratio must be less than 1.0.B) Long-term creditors would prefer the times interest earned ratio be 1.4 rather than 1.5.C) The debt-equity ratio can be computed as 1 plus the equity multiplier.D) An equity multiplier of 1.2 means a firm has $1.20 in sales for every $1 in equity.E) An increase in the depreciation expense will not affect the cash coverage ratio.22) If a firm has a debt-equity ratio of 1.0, then its total debt ratio must be which one of the following?A) 0B) .5C) 1.0D) 1.5E) 2.023) The cash coverage ratio directly measures the ability of a company to meet its obligation to pay:A) an invoice to a supplier.B) wages to an employee.C) interest to a lender.D) principal to a lender.E) a dividend to a shareholder.24) All-State Moving had sales of $899,000 in 2017 and $967,000 in 2018. The firm's current accounts remained constant. Given this information, which one of the following statements must be true?A) The total asset turnover rate increased.B) The days' sales in receivables increased.C) The net working capital turnover rate increased.D) The fixed asset turnover decreased.E) The receivables turnover rate decreased.25) The Corner Hardware has succeeded in increasing the amount of goods it sells while holding the amount of inventory on hand at a constant level. Assume that both the cost per unit and the selling price per unit also remained constant. This accomplishment will be reflected in the firm's financial ratios in which one of the following ways?A) Decrease in the inventory turnover rateB) Decrease in the net working capital turnover rateC) Increase in the fixed asset turnover rateD) Decrease in the day's sales in inventoryE) Decrease in the total asset turnover rate26) RJ's has a fixed asset turnover rate of 1.26 and a total asset turnover rate of .97. Sam's has a fixed asset turnover rate of 1.31 and a total asset turnover rate of .94. Both companies have similar operations. Based on this information, RJ's must be doing which one of the following?A) Utilizing its fixed assets more efficiently than Sam'sB) Utilizing its total assets more efficiently than Sam'sC) Generating $1 in sales for every $1.26 in net fixed assetsD) Generating $1.26 in net income for every $1 in net fixed assetsE) Maintaining the same level of current assets as Sam's27) Ratios that measure how efficiently a firm manages its assets and operations to generate net income are referred to as ________ ratios.A) asset managementB) long-term solvencyC) short-term solvencyD) profitabilityE) turnover28) If a company produces a return on assets of 14 percent and also a return on equity of 14 percent, then the firm:A) may have short-term, but not long-term debt.B) is using its assets as efficiently as possible.C) has no net working capital.D) has a debt-equity ratio of 1.0.E) has an equity multiplier of 1.0.29) Which one of the following will decrease if a firm can decrease its operating costs, all else constant?A) Return on equityB) Return on assetsC) Profit marginD) Total asset turnoverE) Price-earnings ratio30) Al's has a price-earnings ratio of 18.5. Ben's also has a price-earnings ratio of 18.5. Which one of the following statements must be true if Al's has a higher PEG ratio than Ben's?A) Al's has more net income than Ben's.B) Ben's is increasing its earnings at a faster rate than Al's.C) Al's has a higher market value per share than does Ben's.D) Ben's has a lower market-to-book ratio than Al's.E) Al's has a higher earnings growth rate than Ben's.31) Tobin's Q relates the market value of a firm's assets to which one of the following?A) Initial cost of creating the firmB) Current book value of the firmC) Average asset value of similar firmsD) Average market value of similar firmsE) Today's cost to duplicate those assets32) The price-sales ratio is especially useful when analyzing firms that have:A) volatile market prices.B) negative earnings.C) positive PEG ratios.D) a high Tobin's Q.E) increasing sales.33) Mortgage lenders probably have the most interest in the ________ ratios.A) return on assets and profit marginB) long-term debt and times interest earnedC) price-earnings and debt-equityD) market-to-book and times interest earnedE) return on equity and price-earnings34) Relationships determined from a company's financial information and used for comparison purposes are known as:A) financial ratios.B) identities.C) dimensional analysis.D) scenario analysis.E) solvency analysis.35) DL Farms currently has $600 in debt for every $1,000 in equity. Assume the company uses some of its cash to decrease its debt while maintaining its current equity and net income. Which one of the following will decrease as a result of this action?A) Equity multiplierB) Total asset turnoverC) Profit marginD) Return on assetsE) Return on equity36) Which one of these identifies the relationship between the return on assets and the return on equity?A) Profit marginB) Profitability determinantC) Balance sheet multiplierD) DuPont identityE) Debt-equity ratio37) Which one of the following accurately describes the three parts of the DuPont identity?A) Equity multiplier, profit margin, and total asset turnoverB) Debt-equity ratio, capital intensity ratio, and profit marginC) Operating efficiency, equity multiplier, and profitability ratioD) Return on assets, profit margin, and equity multiplierE) Financial leverage, operating efficiency, and profitability ratio38) An increase in which of the following must increase the return on equity, all else constant?A) Total assets and salesB) Net income and total equityC) Total asset turnover and debt-equity ratioD) Equity multiplier and total equityE) Debt-equity ratio and total debt39) Which one of the following is a correct formula for computing the return on equity?A) Profit margin × ROAB) ROA × Equity multiplierC) Profit margin × Total asset turnover × Debt-equity ratioD) Net income/Total assetsE) Debt-equity ratio × ROA40) The DuPont identity can be used to help managers answer which of the following questions related to a company's operations?I. How many sales dollars are being generated per each dollar of assets?II. How many dollars of assets have been acquired per each dollar in shareholders' equity? III. How much net profit is being generating per dollar of sales?IV. Does the company have the ability to meet its debt obligations in a timely manner?A) I and III onlyB) II and IV onlyC) I, II, and III onlyD) II, III and IV onlyE) I, II, III, and IV41) The U.S. government coding system that classifies a company by the nature of its business operations is known as the:A) Centralized Business Index.B) Peer Grouping codes.C) Standard Industrial Classification codes.D) Governmental ID codes.E) Government Engineered Coding System.42) Which one of the following statements is correct?A) Book values should always be given precedence over market values.B) Financial statements are rarely used as the basis for performance evaluations.C) Historical information is useful when projecting a company's future performance.D) Potential lenders place little value on financial statement information.E) Reviewing financial information over time has very limited value.43) The most acceptable method of evaluating the financial statements is to compare the company's current financial:A) ratios to the company's historical ratios.B) statements to the financial statements of similar companies operating in other countries.C) ratios to the average ratios of all companies located within the same geographic area.D) statements to those of larger companies in unrelated industries.E) statements to the projections that were created based on Tobin's Q.44) All of the following issues represent problems encountered when comparing the financial statements of two separate entities except the issue of the companies:A) being conglomerates with unrelated lines of business.B) having geographically varying operations.C) using differing accounting methods.D) differing seasonal peaks.E) having the same fiscal year.45) Which one of these is the least important factor to consider when comparing the financial situations of utility companies that generate electric power and have the same SIC code?A) Type of ownershipB) Government regulations affecting the firmC) Fiscal year endD) Methods of power generationE) Number of part-time employees46) At the beginning of the year, Brick Makers had cash of $183, accounts receivable of $392, accounts payable of $463, and inventory of $714. At year end, cash was $167, accounts payables was $447, inventory was $682, and accounts receivable was $409. What is the amount of the net source or use of cash by working capital accounts for the year?A) Net use of $16 cashB) Net use of $17 cashC) Net source of $17 cashD) Net source of $15 cashE) Net use of $15 cash47) During the year, Al's Tools decreased its accounts receivable by $160, increased its inventory by $115, and decreased its accounts payable by $70. How did these three accounts affect the sources of uses of cash by the firm?A) Net source of cash of $120B) Net source of cash of $205C) Net source of cash of $45D) Net use of cash of $115E) Net use of cash of $2548) Lani's generated net income of $911, depreciation expense was $47, and dividends paid were $25. Accounts payables increased by $15, accounts receivables increased by $28, inventory decreased by $14, and net fixed assets decreased by $8. There was no interest expense. What was the net cash flow from operating activity?A) $776B) $865C) $959D) $922E) $98549) For the past year, Jenn's Floral Arrangements had taxable income of $198,600, beginning common stock of $68,000, beginning retained earnings of $318,750, ending common stock of $71,500, ending retained earnings of $316,940, interest expense of $11,300, and a tax rate of 21 percent. What is the amount of dividends paid during the year?A) $157,280B) $159,935C) $163,200D) $153,555E) $158,70450) The Floor Store had interest expense of $38,400, depreciation of $28,100, and taxes of $19,600 for the year. At the start of the year, the firm had total assets of $879,400 and current assets of $289,600. By year's end total assets had increased to $911,900 while current assets decreased to $279,300. What is the amount of the cash flow from investment activity for the year?A) −$51,150B) $21,850C) $29,300D) −$70,900E) −$89,40051) Williamsburg Market is an all-equity firm that has net income of $96,200, depreciation expense of $6,300, and an increase in net working capital of $2,800. What is the amount of the net cash from operating activity?A) $91,300B) $99,700C) $93,400D) $105,300E) $113,70052) The accounts payable of a company changed from $136,100 to $104,300 over the course of a year. This change represents a:A) use of $31,800 of cash as investment activity.B) source of $31,800 of cash as an operating activity.C) source of $31,800 of cash as a financing activity.D) source of $31,800 of cash as an investment activity.E) use of $31,800 of cash as an operating activity.53) Oil Creek Auto has sales of $3,340, net income of $274, net fixed assets of $2,600, and current assets of $920. The firm has $430 in inventory. What is the common-size statement value of inventory?A) 12.22 percentB) 44.16 percentC) 16.54 percentD) 13.36 percentE) 46.74 percent54) Pittsburgh Motors has sales of $4,300, net income of $320, total assets of $4,800, and total equity of $2,950. Interest expense is $65. What is the common-size statement value of the interest expense?A) .89 percentB) 1.51 percentC) 1.69 percentD) 2.03 percentE) 1.35 percent55) Last year, which is used as the base year, a firm had cash of $52, accounts receivable of $223, inventory of $509, and net fixed assets of $1,107. This year, the firm has cash of $61,accounts receivable of $204, inventory of $527, and net fixed assets of $1,216. What is this year's common-base-year value of inventory?A) .67B) .91C) .88D) 1.04E) 1.1856) Duke's Garage has cash of $68, accounts receivable of $142, accounts payable of $235, and inventory of $318. What is the value of the quick ratio?A) 2.25B) .53C) .71D) .89E) 1.3557) Uptown Men's Wear has accounts payable of $2,214, inventory of $7,950, cash of $1,263, fixed assets of $8,400, accounts receivable of $3,907, and long-term debt of $4,200. What is the value of the net working capital to total assets ratio?A) .31B) .42C) .47D) .51E) .5658) DJ's has total assets of $310,100 and net fixed assets of $168,500. The average daily operating costs are $2,980. What is the value of the interval measure?A) 31.47 daysB) 47.52 daysC) 56.22 daysD) 68.05 daysE) 104.62 days59) Corner Books has a debt-equity ratio of .57. What is the total debt ratio?A) .36B) .30C) .44D) 2.27E) 2.7560) SS Stores has total debt of $4,910 and a debt-equity ratio of 0.52. What is the value of the total assets?A) $16,128.05B) $7,253.40C) $9,571.95D) $11,034.00E) $14,352.3161) JK Motors has sales of $96,400, costs of $53,800, interest paid of $2,800, and depreciation of $7,100. The tax rate is 21 percent. What is the value of the cash coverage ratio?A) 15.21B) 12.14C) 17.27D) 23.41E) 12.6862) Terry's Pets paid $2,380 in interest and $2,200 in dividends last year. The times interest earned ratio is 2.6 and the depreciation expense is $680. What is the value of the cash coverage ratio?A) 1.42B) 2.72C) 2.94D) 2.89E) 2.4663) The Up-Towner has sales of $913,400, costs of goods sold of $579,300, inventory of $123,900, and accounts receivable of $78,900. How many days, on average, does it take the firm to sell its inventory assuming that all sales are on credit?A) 74.19 daysB) 84.69 daysC) 78.07 daysD) 96.46 daysE) 71.01 days64) Flo's Flowers has accounts receivable of $4,511, inventory of $1,810, sales of $138,609, and cost of goods sold of $64,003. How many days does it take the firm to sell its inventory and collect the payment on the sale assuming that all sales are on credit?A) 11.88 daysB) 22.20 daysC) 16.23 daysD) 14.50 daysE) 18.67 days65) The Harrisburg Store has net working capital of $2,715, net fixed assets of $22,407, sales of $31,350, and current liabilities of $3,908. How many dollars' worth of sales are generated from every $1 in total assets?A) $1.08B) $1.14C) $1.19D) $84E) $9366) TJ's has annual sales of $813,200, total debt of $171,000, total equity of $396,000, and a profit margin of 5.78 percent. What is the return on assets?A) 8.29 percentB) 6.48 percentC) 9.94 percentD) 7.78 percentE) 8.02 percent67) Frank's Used Cars has sales of $807,200, total assets of $768,100, and a profit margin of 6.68 percent. The firm has a total debt ratio of 54 percent. What is the return on equity?A) 13.09 percentB) 12.04 percentC) 11.03 percentD) 8.56 percentE) 15.26 percent68) Bernice's has $823,000 in sales. The profit margin is 4.2 percent and the firm has 7,500 shares of stock outstanding. The market price per share is $16.50. What is the price-earnings ratio?A) 3.58B) 3.98C) 4.32D) 3.51E) 4.2769) Hungry Lunch has net income of $73,402, a price-earnings ratio of 13.7, and earnings per share of $.43. How many shares of stock are outstanding?A) 13,520B) 12,460C) 165,745D) 171,308E) 170,70270) A firm has 160,000 shares of stock outstanding, sales of $1.94 million, net income of $126,400, a price-earnings ratio of 21.3, and a book value per share of $7.92. What is the market-to-book ratio?A) 2.12B) 1.84C) 1.39D) 2.45E) 2.6971) Taylor's Men's Wear has a debt-equity ratio of 48 percent, sales of $829,000, net income of $47,300, and total debt of $206,300. What is the return on equity?A) 19.29 percentB) 11.01 percentC) 15.74 percentD) 18.57 percentE) 14.16 percent72) Nielsen's has inventory of $29,406, accounts receivable of $46,215, net working capital of $4,507, and accounts payable of $48,919. What is the quick ratio?A) 1.55B) .49C) 1.32D) .94E) .9273) The Strong Box has sales of $859,700, cost of goods sold of $648,200, net income of $93,100, and accounts receivable of $102,300. How many days of sales are in receivables?A) 57.60 daysB) 40.32 daysC) 54.53 daysD) 29.41 daysE) 43.43 days74) Corner Books has sales of $687,400, cost of goods sold of $454,200, and a profit margin of 5.5 percent. The balance sheet shows common stock of $324,000 with a par value of $5 a share, and retained earnings of $689,500. What is the price-sales ratio if the market price is $43.20 per share?A) 4.28B) 12.74C) 6.12D) 4.07E) 14.5175) Gem Jewelers has current assets of $687,600, total assets of $1,711,000, net working capital of $223,700, and long-term debt of $450,000. What is the debt-equity ratio?A) .87B) .94C) 1.21D) 1.15E) 1.0676) Russell's has annual sales of $649,200, cost of goods sold of $389,400, interest of $23,650, depreciation of $121,000, and a tax rate of 21 percent. What is the cash coverage ratio for the year?A) 8.43B) 10.99C) 11.64D) 5.87E) 18.2277) Lawn Care, Inc., has sales of $367,400, costs of $183,600, depreciation of $48,600, interest of $39,200, and a tax rate of 25 percent. The firm has total assets of $422,100, long-term debt of $102,000, net fixed assets of $264,500, and net working capital of $22,300. What is the return on equity?A) 24.26 percentB) 15.38 percentC) 38.96 percentD) 29.96 percentE) 17.06 percent78) Frank's Welding has net fixed assets of $36,200, total assets of $51,300, long-term debt of $22,000, and total debt of $29,700. What is the net working capital to total assets ratio?A) 12.18 percentB) 16.82 percentC) 14.42 percentD) 17.79 percentE) 9.90 percent79) The Green Fiddle has current liabilities of $28,000, sales of $156,900, and cost of goods sold of $62,400. The current ratio is 1.22 and the quick ratio is .71. How many days on average does it take to sell the inventory?A) 128.13 daysB) 74.42 daysC) 199.81 daysD) 147.46 daysE) 83.53 days80) Green Yard Care has net income of $62,300, a tax rate of 21 percent, and a profit margin of 6.7 percent. Total assets are $1,100,500 and current assets are $328,200. How many dollars of sales are being generated from every dollar of net fixed assets?A) $2.83B) $1.37C) $.84D) $1.20E) $1.2381) Jensen's Shipping has total assets of $694,800 at year's end. The beginning owners' equity was $362,400. During the year, the company had sales of $711,000, a profit margin of 5.2 percent, a tax rate of 21 percent, and paid $12,500 in dividends. What is the equity multiplier at year-end?A) 1.67B) 1.72C) 1.93D) 1.80E) 1.8682) Western Gear has net income of $12,400, a tax rate of 21 percent, and interest expense of $1,600. What is the times interest earned ratio for the year?A) 9.63B) 7.75C) 10.81D) 14.97E) 10.9783) Big Tree Lumber has earnings per share of $1.36. The firm's earnings have been increasing at an average rate of 2.9 percent annually and are expected to continue doing so. The firm has 21,500 shares of stock outstanding at a price per share of $23.40. What is the firm's PEG ratio?A) 2.27B) 11.21C) 4.85D) 3.94E) 5.9384) Townsend Enterprises has a PEG ratio of 5.3, net income of $49,200, a price-earnings ratio of 17.6, and a profit margin of 7.1 percent. What is the earnings growth rate?A) 2.48 percentB) 1.06 percentC) 3.32 percentD) 5.20 percentE) 10.60 percent85) A firm has total assets with a current book value of $71,600, a current market value of $82,300, and a current replacement cost of $90,400. What is the value of Tobin's Q?A) .85B) .87C) .90D) .94E) .9186) Dixie Supply has total assets with a current book value of $368,900 and a current replacement cost of $486,200. The market value of these assets is $464,800. What is the value of Tobin's Q?A) .79B) .76C) .96D) 1.26E) 1.0587) Dandelion Fields has a Tobin's Q of .96. The replacement cost of the firm's assets is $225,000 and the market value of the firm's debt is $101,000. The firm has 20,000 shares of stock outstanding and a book value per share of $2.09. What is the market-to-book ratio?A) 2.75 timesB) 3.18 timesC) 3.54 timesD) 4.01 timesE) 4.20 times88) The Tech Store has annual sales of $416,000, a price-earnings ratio of 18, and a profit margin of 3.7 percent. There are 12,000 shares of stock outstanding. What is the price-sales ratio?A) .97B) .67C) 1.08D) 1.15E) .8689) Lassiter Industries has annual sales of $328,000 with 8,000 shares of stock outstanding. The firm has a profit margin of 4.5 percent and a price-sales ratio of 1.20. What is the firm's price-earnings ratio?A) 21.9B) 17.4C) 18.6D) 26.7E) 24.390) Drive-Up has sales of $31.4 million, total assets of $27.6 million, and total debt of $14.9 million. The profit margin is 3.7 percent. What is the return on equity?A) 6.85 percentB) 9.15 percentC) 11.08 percentD) 13.31 percentE) 14.21 percent91) Corner Supply has a current accounts receivable balance of $246,000. Credit sales for the year just ended were $2,430,000. How many days on average did it take for credit customers to pay off their accounts during this past year?A) 44.29 daysB) 55.01 daysC) 55.50 daysD) 36.95 daysE) 41.00 days92) BL Industries has ending inventory of $302,800, annual sales of $2.33 million, and annual cost of goods sold of $1.41 million. On average, how long did a unit of inventory sit on the shelf before it was sold?A) 47.43 daysB) 22.18 daysC) 78.38 daysD) 61.78 daysE) 83.13 days93) Billings Inc. has net income of $161,000, a profit margin of 7.6 percent, and an accounts receivable balance of $127,100. Assume that 66 percent of sales are on credit. What is the days' sales in receivables?A) 21.90 daysB) 27.56 daysC) 33.18 daysD) 35.04 daysE) 36.19 days94) Stone Walls has a long-term debt ratio of .6 and a current ratio of 1.2. Current liabilities are $800, sales are $7,800, the profit margin is 6.5 percent, and return on equity is 15.5 percent. What is the amount of the firm's net fixed assets?A) $8,880.15B) $8,017.43C) $7,666.67D) $5,848.15E) $8,977.43。

chapter 3&4提纲答案

• 40.It seems that she enjoys light music very much. • 41.He said nothing and went to the cinema. • 42.I don’t draw as well as her.或 • I draw worse than her. • 43.If you work hard, you’ll learn English well. • 44.If you don’t hurry up, you’ll be late for school. • 45.You will fail the exam unless you work hard.
• 54.Most boys are interested in playing football. • Most boys like playing football best. • 55.If it doesn’t rain, we will go to the park. • 56.My bike goes wrong. • 57.Could you show me how I can get to the station?
• 7. It is great fun walking along the paths near the river. • 8. What do you think of walking in the snow? • 9.It took them two years to build the museum. • 10.The shop is open between 9 a.m. and 10 p.m. • 11.To go hiking on the Great Wall in some other places is also great fun. • 12.It took a long time to build the bridge. • 13.We would thank you for information about places of interest in and around Beijing.

同济大学_汽车学院_汽车振动_郭荣_chapter3_作业答案

2、拉格朗日法：
1 1 2 12 + m2 x 2 T = m1 x 2 2
U=
1 2 1 1 2 ⎤ k1 x1 + k2 (2 x2 − x1 ) 2 = ⎡ (k1 + k2 ) x12 + 4k2 x1 x2 + 4k2 x2 ⎣ ⎦ 2 2 2
Dr. Rong Guo
School of automotive studies, tongji university
取质量中心的平动和转动为两个运动坐标试确定该系统的刚度矩阵和质量矩阵并求系统的特征值和特征向量
《机械振动学》第三章习题答案
3.1 图示不计质量的刚杆，长度为 2l，在其中点和左端附以质量 m1 , m2 ，两端的（注：分别使用直接法和拉格朗日法，弹簧刚度为 k1 , k2 。求此系统的运动方程。运动方程写成矩阵形式）
-6-
⎡ k2 ⎢ −k Kb = ⎢ 2 ⎢ 0 ⎢ ⎣ 0
− k2 k 2 + k3 − k3 0
0 − k3 k3 + k 4 − k4
0 ⎤ 0 ⎥ ⎥ − k4 ⎥ ⎥ k4 ⎦
School of automotive studies, tongji university
《机械振动学》第三章习题答案
②
k 2 1 = k1 2 = 0
θ1 = 0, θ 2 = 1
k22 = m2 gl2
⎡( m + m2 ) gl1 0 ⎤ K =⎢ 1 ⎥ m2 gl2 ⎦ 0 ⎣
质量矩阵：
= 1, θ = 0 ① θ 1 2
m21 = m12 = m2l1l2 m11 = m1l12 + m2l1 ( l1 + l2 ) − m2l1l2 = ( m1 + m2 ) l12

平狄克微观经济学第六版第三章课后答案

PART IIPRODUCERS, CONSUMERS, AND COMPETITIVE MARKETSCHAPTER 3CONSUMER BEHAVIORChapter 3 builds the foundation for deriving the demand curve in Chapter 4. In order tounderstand demand theory, students must have a firm grasp of indifference curves, the marginal rateof substitution, the budget line, and optimal consumer choice. It is possible to discuss consumer choicewithout going into extensive detail on utility theory. Many students find utility functions to be a moreabstract concept than preference relationships. However, if you plan to discuss uncertainty in Chapter5, you will need to cover marginal utility (section 3.5). Even if you cover utility theory only briefly,make sure students are comfortable with the term utility because it appears frequently in Chapter 4.When introducing indifference curves, stress that physical quantities are represented on thetwo axes. After discussing supply and demand, students may think that price should be on the verticalaxis. To illustrate the indifference curves, pick an initial bundle on the graph and ask which otherbundles are likely to be more preferred and less preferred to the initial bundle. This will divide thegraph into four quadrants, and it is then easier for students to figure out the set of bundles betweenwhich the consumer is indifferent. It is helpful to present a lot of examples with different types ofgoods and see if the class can figure out how to draw the indifference curves. The examples are alsouseful for explaining the significance of the assumptions made about preferences. In presentingdifferent examples, you can ask which assumption would be violated.Explaining utility follows naturally from the discussion of indifference curves. Though anabstract concept, it is possible to get students to understand the basic idea without spending too muchtime on the topic. You might point out that we as consumers have a goal in life, which is to maximizeour utility subject to our budget constraint. When we go to the store we pick the basket that we likebest and that stays within our budget. From this we derive demand curves. Emphasize that it is theranking that is important and not the utility number, and point out that if we can graph an indifferencecurve we can certainly find an equation to represent it. Finally, what is most important is the rate atwhich consumers are willing to exchange goods (the marginal rate of substitution) and this is based onthe relative satisfaction that they derive from each good at any particular time.The marginal rate of substitution, MRS, can be confusing to students. Some confuse the MRSwith the ratio of the two quantities. If this is the case, point out that the slope is equal to the ratio of the rise, ∆Y, and the run, ∆X. This ratio is equal to the ratio of the intercepts of a line just tangent to the indifference curve. As we move along a convex indifference curve, these intercepts and the MRSchange. Another problem is the terminology “of X for Y.” This is confus ing because we are notsubstituting “X for Y,” but Y for one unit of X. You may want to present a variety of examples in classto explain this important concept.1. What are the four basic assumptions about individual preferences? Explain thesignificance or meaning of each.(1) Preferences are complete: this means that the consumer is able to compare andrank all possible baskets; (2) Preferences are transitive: this means that preferencesare consistent, in that if bundle A is preferred to bundle B and bundle B is preferredto bundle C, then we should be able to conclude that bundle A is preferred to bundleC; (3) More is preferred to less: this means that all goods are desirable, and that theconsumer will always prefer to have more of a good; (4) Diminishing marginal rateof substitution: this means that indifference curves are convex, and that the slope ofthe indifference curve increases (becomes less negative) as we move down along thecurve. As a consumer moves down along her indifference curve she is willing to giveup fewer units of the good on the vertical axis in exchange for one more unit of thegood on the horizontal axis. This assumption also means that balanced marketbaskets are preferred to baskets that have a lot of one good and very little of theother good.2. Can a set of indifference curves be upward sloping? If so, what would this tell you about the two goods?A set of indifference curves can be upward sloping if we violate assumption numberthree; more is preferred to less. When a set of indifference curves is upward sloping,it means one of the goods is a “bad” in that the consumer prefers less of the goodrather than more of the good. The positive slope means that the consumer willaccept more of the bad good only if she also receives more of the other good in return.As we move up along the indifference curve the consumer has more of the good sheb.Draw a set of indifference curves for Jon.Since Jon is always willing to trade one can of coke for one can of sprite, hisindifference curves are linear with a slope of –1.c.Draw two budget lines with different slopes and illustrate the satisfaction-maximizing choice. What conclusion can you draw?Jon’s indifference curves are linear with a slope of –1. Jon’s budget line is alsolinear, and will have a slope that reflects the ratio of the two prices. If Jon’s budgetline is steeper than his indifference curves then he will choose to consume only thegood on the vertical axis. If Jon’s b udget line is flatter than his indifference curvesthen he will choose to consumer only the good on the horizontal axis. Jon willalways choose a corner solution, unless his budget line has the same slope as hisindifference curves. In this case any combination of Sprite and Coke that uses uphis entire income with maximize his satisfaction.5. What happens to the marginal rate of substitution as you move along a convex indifference curve? A linear indifference curve?The MRS measures how much of a good you are willing to give up in exchange for onemore unit of the other good, keeping utility constant. The MRS diminishes along aconvex indifference curve in that as you move down along the indifference curve, youare willing to give up less and less of the one good in exchange for the other. TheMRS is also the slope of the indifference curve, which increases (becomes lessnegative) as you move down along the indifference curve. The MRS is constantalong a linear indifference curve, since in this case the slope does not change. Theconsumer is always willing to trade the same number of units of one good inexchange for the other.6. Explain why an MRS between two goods must equal the ratio of the price of the goods for the consumer to achieve maximum satisfaction.The MRS describes the rate at which the consumer is willing to trade one good foranother to maintain the same level of satisfaction. The ratio of prices describes thetrade-off that the market is willing to make between the same two goods. Thetangency of the indifference curve with the budget line represents the point at whichthe trade-offs are equal and consumer satisfaction is maximized. If the MRS betweentwo goods is not equal to the ratio of prices, then the consumer could trade one good foranother at market prices to obtain higher levels of satisfaction. For example, if theslope of the budget line (the ratio of the prices) is –4 then the consumer can trade 4units of good 2 for one unit of good 1. If the MRS at the current bundle is –6, then theconsumer is willing to trade 6 units of good 2 for one unit of good 1. Since the twoslopes are not equal the consumer is not maximizing her satisfaction. The consumer iswilling to trade 6 but only has to trade 4, so she should make the trade. This tradingcontinues until the highest level of satisfaction is achieved. As trades are made, theMRS will change and become equal to the price ratio.7. Describe the indifference curves associated with two goods that are perfect substitutes. What if they are perfect complements?Two goods are perfect substitutes if the MRS of one for another is a constant number.Given the MRS is a constant number, the slope of the indifference curves will beconstant, and the indifference curves are therefore linear. If two goods are perfectcomplements, the indifference curves are L-shaped. In this case the consumerwants to consume the two goods in a fixed proportion, say one unit of good 1 for every1 unit of good 2. If she has more of one good but not more of the other then she doesnot get any extra satisfaction.8. What is the difference between ordinal utility and cardinal utility? Explain why the assumption of cardinal utility is not needed in order to rank consumer choices.Ordinal utility implies an ordering among alternatives without regard for intensity ofpreference. For example, if the consumer’s first choice is preferred to their secondchoice, then utility from the first choice will be higher than utility from the secondchoice. How much higher is not important. An ordinal utility function generates aranking of bundles and no meaning is given to the utility number itself. Cardinalutility implies that the intensity of preferences may be quantified, and that the utilitynumber itself has meaning. An ordinal ranking is all that is needed to rank consumerchoices. It is not necessary to know how intensely a consumer prefers basket A overbasket B; it is enough to know that A is preferred to B.9. Upon merging with the West German economy, East German consumers indicated a preference for Mercedes-Benz automobiles over Volkswagens. However, when they converted their savings into deutsche marks, they flocked to Volkswagen dealerships. How can you explain this apparent paradox?Three assumptions are required to address this question: 1) that a Mercedes costs morethan a Volkswagen; 2) that the East German consumers’ utility function comprises twogoods, automobiles and all other goods evaluated in deutsche marks; and 3) that EastGermans have incomes. Based on these assumptions, we can surmise that while EastGerman consumers may prefer a Mercedes to a Volkswagen, they either cannot afford aMercedes or they prefer a bundle of other goods plus a Volkswagen to a Mercedes alone.While the marginal utility of consuming a Mercedes exceeds the marginal utility ofconsuming a Volkswagen, the consumer will consider marginal utility per dollar foreach good. This means the marginal utility per dollar must have been higher for theVolkswagen since consumers flocked to the Volkswagen dealerships and not theMercedes dealerships.10. Draw a budget line and then draw an indifference curve to illustrate the satisfaction maximizing choice associated with two products. Use your graph to answer the following questions.a.Suppose that one of the products is rationed. Explain why the consumer is likelyto be worse off.When goods are not rationed, the consumer is able to choose the satisfaction-maximizing bundle where the slope of the budget line is equal to the slope of theindifference curve, or the price ratio is equal to the MRS. This is point A in the graphbelow. If good 1 is now rationed the consumer will not be able to attain the utilitymaximizing point. He or she will have to consume more of the other good instead.This is point B below.b.Suppose now that the price of one of the products is fixed at a level below thecurrent price. As a result, the consumer is not able to purchase as much as she would like of the product. Can you tell if the consumer is better off or worse off?When the price of the good is fixed at a level below the current (equilibrium) price,there will be a shortage of the good and the good will have to be effectively rationed.As in the question above, the consumer is worse off because she is not able to attainher utility maximizing point.11. Based on his preferences, Bill is willing to trade 4 movie tickets for 1 ticket to a basketball game. If movie tickets cost $8 each and a ticket to the basketball game costs $40, should Bill make the trade? Why or why not?No Bill should not make the trade. If he gives up the 4 movie tickets then he willsave $8 per ticket for a total of $32. However, this is not enough for a basketballticket. He would in fact have to give up 5 movie tickets if he wanted to buy anotherbasketball ticket. Notice also, that the marginal utility per dollar is higher for movietickets so Bill will be better off if he consumes more movie tickets and fewerbasketball tickets. To figure this out recall that what Bill is willing to do defines hisMRS. His MRS is 4 so this means that the marginal utility of a basketball game is 4and the marginal utility of a movie is 1:MRS=-4=-MUballMUmovie=-41.Now the marginal utility per dollar can be computed:MUball Pball =440=110MUmovie Pmovie =18.12. Describe the equal marginal principle. Explain why this principle may not hold if increasing marginal utility is associated with the consumption of one or both goods.The equal marginal principle states that the ratio of the marginal utility to price mustbe equal across all goods to obtain maximum satisfaction. In other words, utilitymaximization is achieved when the budget is allocated so that the marginal utility perdollar of expenditure is the same for each good. If the marginal utility per dollar is notequal then utility can be increased by allocating more dollars to the good with thehigher marginal utility per dollar. The consumer will obtain more “bang for the buck”if they reallocate their dollars.If marginal utility is increasing, the consumer maximizes satisfaction by consumingever larger amounts of the good. Thus, the consumer would spend all income on onegood, assuming a constant price, resulting in a corner solution. With a corner solution,the equal marginal principle cannot hold.13. The price of computers has fallen substantially over the past two decades. Use this drop in price to explain why the Consumer Price Index is likely to overstate substantially the cost-of-living index for individuals who use computers intensively.The consumer price index measures the cost of a typical basket of goods purchased bythe consumer in the current year relative to the cost of the basket in the base year.Each good in the basket is assigned a weight, which reflects the importance of the goodto the consumer, and the weights are kept fixed from year to year. The problem withfixing the weights is that consumers will shift their purchases from year to year to givemore weight to goods whose prices have fallen, and less weight to goods whose priceshave risen. The CPI will therefore give too much weight to goods whose prices haverisen, and too little weight to goods whose prices have fallen. For the individual whouses computers intensively, the fixed weight for computers in the basket willunderstate the importance of this good, and will hence understate the effect of the fallin the price of computers. The CPI will overstate the rise in the cost of living for thistype of individual.14. Explain why the Paasche index will generally understate the ideal cost-of-living index.The Paasche index measures the current cost of the current bundle of goods relativeto the base year cost of the current bundle of goods. The Paasche index willunderstate the ideal cost of living because it assumes the individual will buy thecurrent year bundle in the base period. In reality, at base year prices the consumerwould have been able to attain the same level of utility at a lower cost by alteringtheir consumption bundle. Since the base year cost is overstated, the denominatorwill be larger and the index will be lower, or understated.1. In this chapter, consumer preferences for various commodities did not change during the analysis. Yet in some situations, preferences do change as consumption occurs. Discuss why and how preferences might change over time with consumption of these two commodities:a. cigarettesThe assumption that preferences do not change is a reasonable one if choices areindependent across time. It does not hold, however, when “habit-forming” or addictivebehavior is involved, as in the case of cigarettes: the consumption of cigarettes in oneperiod influences their consumption in the next period.b. dinner for the first time at a restaurant with a special cuisineThis example is parallel to examples of adventure seeking. For some, a new diningexperience creates enthusiasm to seek out more exciting and different cuisines anddishes. For others, they develop a fondness for regularity and consistency or fear ofthe new and unknown. In either of these cases, choices change as consumption occurs.2. Draw indifference curves that represent the following individuals’ preferences for hamburgers and soft drinks. Indicate the direction in which the individuals’ satisfaction (or utility) is increasing.a.Joe has convex preferences and dislikes both hamburgers and soft drinks.Since Joe dislikes both goods, his set of indifference curves will be bowed inwardstowards the origin instead of outwards, as in the normal case where more is preferredto less. Given he dislikes both goods, his satisfaction is increasing in the direction ofthe origin. Convexity of preferences implies his indifference curves will have thenormal shape in that they are bowed towards the direction of increasing satisfaction.Convexity also implies that given any two bundles between which the consumer isindifferent, the “average” of the two bundles will be in the preferred set, or wi ll leavehim at least as well off.so ft dr in kb.Jane loves hamburgers and dislikes soft drinks. If she is served a soft drink, shewill pour it down the drain rather than drink it.Since Jane can freely dispose of the soft drink if it is given to her, she considers it to be aneutral good. This means she does not care about soft drinks one way or the other.With hamburgers on the vertical axis, her indifference curves are horizontal lines. Herso ft dr in kc.Bob loves hamburgers and dislikes soft drinks. If he is served a soft drink, he willdrink it to be polite.Since Bob will drink the soft drink in order to be polite, it can be thought of as a “bad”.When served another soft drink, he will require more hamburgers at the same timein order to keep his satisfaction constant. More soft drinks without morehamburgers will worsen his utility. More hamburgers and fewer soft drinks willincrease his utility.s o ft d rin kd.Molly loves hamburgers and soft drinks, but insists on consuming exactly one softdrink for every two hamburgers that she eats.Molly wants to consume the two goods in a fixed proportion so her indifference curvesare L-shaped. For any given amount of one good, she gets no extra satisfaction fromhaving more of the other good. She will only increase her satisfaction if she hasmore of both goods.s o ft d rin ke.Bill likes hamburgers, but neither likes nor dislikes soft drinks.Like Jane, Bill considers soft drinks to be a neutral good. Since he does not careabout soft drinks one way or the other we can assume that no matter how many hehas, his utility will be the same. His level of satisfaction depends entirely on hows o ft d rin kf.Mary always gets twice as much satisfaction from an extra hamburger as she doesfrom an extra soft drink.How much extra satisfaction Mary gains from an extra hamburger or soft drink tellsus something about the marginal utilities of the two goods, or about her MRS. If shealways receives twice the satisfaction from an extra hamburger then her marginalutility from consuming an extra hamburger is twice her marginal utility fromconsuming an extra soft drink. Her MRS, with hamburgers on the vertical axis, is1/2.so ft dr in k3. If Jane is currently willing to trade 4 movie tickets for 1 basketball ticket then she must like basketball better than movies. True or false? Explain.This statement is not necessarily true. If she is always willing to trade 4 movietickets for 1 basketball ticket then yes she likes basketball better because she willalways gain the same satisfaction from 4 movie tickets as she does from 1 basketballticket. However, it could be that she has convex preferences (diminishing marginalrate of substitution) and is at a bundle where she has a lot of movie tickets relative tobasketball tickets. This would make her willing to give up more movie tickets to getanother basketball ticket. It would not mean though that she liked basketball better.Her willingness to give up a good would in this case depend on the quantity of eachgood in her current basket.4. Janelle and Brian each plan to spend $20,000 on the styling and gas mileage features of a new car. They can each choose all styling, all gas mileage, or some combination of the two. Janelle does not care at all about styling and wants the best gas mileage possible. Brian likes both equally and wants to spend an equal amount on the two features. Using indifference curves and budget lines, illustrate the choice that each person will make.Assume styling is on the vertical axis and gas mileage is on the horizontal axis.Janelle has indifference curves that are vertical. If the styling is there she will takeit, but she otherwise does not care about it. As her indifference curves move over tothe right, she gains more gas mileage and more satisfaction. She will spend all$20,000 on gas mileage. Brian has indifference curves that are L-shaped. He willnot spend more on one feature than on the other feature. He will spend $10,000 onstyling and $10,000 on gas mileage.5. Suppose that Bridget and Erin spend their income on two goods, food (F) and clothing(C). Bridget’s preferences are represented by the utility function U(F,C)=10FC, while Erin’s preferences are represented by the utility function U(F,C)=.20F2C2.a.On a graph, with food on the horizontal axis and clothing on the vertical axis,identify the set of points that give Bridget the same level of utility as the bundle (10,5). Do the same for Erin on a separate graph.Bridget receives a utility of 10*10*5=500 from this bundle. The indifference curve isrepresented by the equation 10FC=500 or FC=50. Some bundles on this indifferencecurve are (5,10), (10,5), (25,2), and (2,25). Erin receives a utilityof .2*10*10*5*5=500 from the bundle (10,5). Her indifference curve is representedby the equation 500=.2F2C2, or 50=FC. This is the same indifference curve asBridget. Both indifference curves have the normal, convex shape.b.On the same two graphs, identify the set of bundles that give Bridget and Erin thesame level of utility as the bundle (15,8).For each person, plug in F=15 and C=8 into their respective utility functions. ForBridget, this gives her a utility of 1200, so her indifference curve is given by theequation 10FC=1200, or FC=120. Some bundles on this indifference curve are(12,10), (10,12), (3,40), and (40,3). For Erin, this bundle gives her a utility of 2880,so her indifference curve is given by the equation 2880=.2F2C2, or FC=120.This is the same indifference curve as Bridget.c.Do you think Bridget and Erin have the same preferences or different preferences?Explain.They have the same preferences because for any given bundle they have the samelevel of utility. This means that they will rank all bundles in the same order. Notehowever, that it is not necessary that they receive the same level of utility to have thesame set of preferences. All that is necessary is that they rank the bundles in thesame order.6. Suppose that Jones and Smith have each decided to allocate $1,000 per year to an entertainment budget in the form of hockey games or rock concerts. They both like hockey games and rock concerts and will choose to consume positive quantities of both goods. However, they differ substantially in their preferences for these two forms of entertainment. Jones prefers hockey games to rock concerts, while Smith prefers rock concerts to hockey games.a. Draw a set of indifference curves for Jones and a second set for Smith.Given they each like both goods and they will each choose to consume positivequantities of both goods, we can assume their indifference curves have the normalconvex shape. However since Jones has an overall preference for hockey and Smithhas an overall preference for rock concerts, their two sets of indifference curves willhave different slopes. Suppose that we place rock concerts on the vertical axis andhockey games on the horizontal axis, Jones will have a larger MRS than Smith.Jones is willing to give up more rock concerts in exchange for a hockey game since heprefers hockey games. The indifference curves for Jones will be steeper.b. Using the concept of marginal rate of substitution, explain why the two sets ofcurves are different from each other.At any combination of hockey games and rock concerts, Jones is willing to give up morerock concerts for an additional hockey game, whereas, Smith is willing to give up fewerrock concerts for an additional hockey game. Since the MRS is a measure of how manyof one good (rock concerts) an individual is willing to give up for an additional unit ofthe other good (hockey games), then the MRS, and hence the slope of the indifferencecurves, will be different for the two individuals.7. The price of DVDs (D) is $20 and the price of CDs (C) is $10. Philip has a budget of $100 to spend on the two goods. Suppose that he has already bought one DVD and one CD. In addition there are 3 more DVDs and 5 more CDs that he would really like to buy.a.Given the above prices and income, draw his budget line on a graph with CDs onthe horizontal axis.His budget line is PD D+PCC=I, or 20D+10C=100. If he spends his entire incomeon DVD’s he could afford to buy 5. If he spends his entire income on CD’s he couldafford to buy 10.b.Considering what he has already purchased, and what he still wants to purchase,identify the three different bundles of CDs and DVDs that he could choose.Assume that he cannot purchase fractional units for this part of the question.Given he has already purchased one of each, for a total of $30, he has $70 left. Sincehe wants 3 more DVD’s he can buy these for $60 and spend his remaining $10 on 1CD. This is the first bundle below. He could also choose to buy only 2 DVD’s for$40 and spend the remaining $30 on 3 CD’s. He can choose the following bundles: Purchased Quantities Total QuantitiesD C D C3 1 2 62 3 3 41 5 4 28. Anne has a job that requires her to travel three out of every four weeks. She has an annual travel budget and can either travel by train or by plane. The airline she typically flies with has a frequent traveler program that reduces the cost of her tickets depending on the number of miles she has flown in a given year. When she reaches 25,000 miles the airline will reduce the price of her tickets by 25% for the remainder of the year. When she reached 50,000 miles, the airline will reduce the price of her tickets by 50% for the remainder of the year. Graph Anne’s budget line, with train miles on the vertical axis and plane miles on the horizontal axis.The typical budget line is linear (with a constant slope) because the prices of the twogoods do not change as the consumer buys more or less of a particular good. In thiscase, the price of airline miles will change depending on how many miles shepurchases. As the price changes, the slope of the budget line will change. Sincethere are three prices, there will be three slopes, or two kinks, to the budget line.Since the price falls as she flies more miles, the budget line will become flatter withevery price change. See the graph in the problem below.9. Debra usually buys a soft drink when she goes to a movie theater, where she has a choice of three sizes: the 8 ounce drink costs $1.50, the 12 ounce drink, $2.00, and the 16 ounce drink, $2.25. Describe the budget constraint that Debra faces when deciding how many ounces of the drink to purchase. (Assume that Debra can costlessly dispose of any of the soft drink that she does not want.First notice that as the size of the drink increases, the price per ounce decreases.When she buys the 8-ounce soft drink she pays $1.508oz$0.19 per oz.When shebuys the 12-ounce size she pays $0.17 per ounce, and when she buys the 16-ounce size, she pays $0.14 per ounce. Given that there are three different prices per ounce of soft drink, the budget line will have two kinks in it, as illustrated below. Notice that at each kink, the slope of the budget line gets flatter (due to the decreasing cost per ounce relative to the “other good” on the vertical axis).O u n ces o fS o ft D rin k 81216。

经济学原理曼昆课后答案chapter3

Problems and Applications1.In the text example of the farmer and the rancher, the farmer’s opportunity cost ofproducing one pound of meat is two pounds of potatoes because for every 20 hours of work, he can produce one pound of meat or two pounds of potatoes. Withlimited time at his disposal, producing a pound of meat means he gives up theopportunity to produce two pounds of potatoes. Similarly, the rancher’s opportunity cost of producing one pound of meat is 1/8 pound of potatoes because for everyhour of work, she can produce one pound of meat or 1/8 pound of potatoes. Withlimited time at her disposal, producing a pound of meat means she gives up theopportunity to produce 1/8 pound of potatoes.2. a.See Figure 3-2. If Maria spends all five hours studying economics, she canread 100 pages, so that is the vertical intercept of the production possibilitiesfrontier. If she spends all five hours studying sociology, she can read 250pages, so that is the horizontal intercept. The time costs are constant, sothe production possibilities frontier is a straight line.Figure 3-2b.It takes Maria two hours to read 100 pages of sociology. In that time, shecould read 40 pages of economics. So the opportunity cost of 100 pages ofsociology is 40 pages of economics.3. a.Workers needed to make:One Car One Ton of Grain U.S.1/41/10Japan1/41/5b.See Figure 3-3. With 100 million workers and four cars per worker, if eithereconomy were devoted completely to cars, it could make 400 million cars.Since a U.S. worker can produce 10 tons of grain, if the U.S. produced onlygrain it would produce 1,000 million tons. Since a Japanese worker canproduce 5 tons of grain, if Japan produced only grain it would produce 500million tons. These are the intercepts of the production possibilities frontiers shown in the figure. Note that since the tradeoff between cars and grain isconstant, the production possibilities frontier is a straight line.Figure 3-3c.Since a U.S. worker produces either 4 cars or 10 tons of grain, theopportunity cost of 1 car is 2½ tons of grain, which is 10 divided by 4.Since a Japanese worker produces either 4 cars or 5 tons of grain, theopportunity cost of 1 car is1 1/4 tons of grain, which is 5 divided by 4. Similarly, the U.S. opportunitycost of 1 ton of grain is 2/5 cars (4 divided by 10) and the Japaneseopportunity cost of 1 ton of grain is 4/5 cars (4 divided by 5). This gives the following table:Opportunity Cost of:1 Car (in terms of tons ofgrain given up)1 Ton of Grain (in termsof cars given up)U.S. 2 1/22/5Japan 1 1/44/5d.Neither country has an absolute advantage in producing cars, since they’reequally productive (the same output per worker); the U.S. has an absoluteadvantage in producing grain, since it’s more productive (greater output perworker).e.Japan has a comparative advantage in producing cars, since it has a loweropportunity cost in terms of grain given up. The U.S. has a comparativeadvantage in producing grain, since it has a lower opportunity cost in termsof cars given up.f.With half the workers in each country producing each of the goods, the U.S.would produce 200 million cars (that’s 50 million workers times 4 cars each)and 500 million tons of grain (50 million workers times 10 tons each).Japan would produce 200 million cars (50 million workers times 4 cars each)and 250 million tons of grain (50 million workers times 5 tons each).g.From any situation with no trade, in which each country is producing somecars and some grain, suppose the U.S. changed 1 worker from producingcars to producing grain. That worker would produce 4 fewer cars and 10additional tons of grain. Then suppose the U.S. offers to trade 7 tons ofgrain to Japan for 4 cars. The U.S. will do this because it values 4 cars at 10tons of grain, so it will be better off if the trade goes through. SupposeJapan changes 1 worker from producing grain to producing cars. Thatworker would produce 4 more cars and 5 fewer tons of grain. Japan willtake the trade because it values 4 cars at 5 tons of grain, so it will be betteroff. With the trade and the change of 1 worker in both the U.S. and Japan,each country gets the same amount of cars as before and both get additionaltons of grain (3 for the U.S. and 2 for Japan). Thus by trading and changingtheir production, both countries are better off.4. a.Pat’s opportunity cost of making a pizza is 1/2 gallon of root beer, since shecould brew 1/2 gallon in the time (2 hours) it takes her to make a pizza. Pathas an absolute advantage in making pizza since she can make one in twohours, while it takes Kris four hours. Kris’s opportunity cost of making apizza is 2/3 gallons of root beer, since she could brew 2/3 of a gallon in thetime (4 hours) it takes her to make a pizza. Since Pat’s opportunity cost ofmaking pizza is less than Kris’s, Pat has a comparative advantage in makingpizza.b.Since Pat has a comparative advantage in making pizza, she will make pizzaand exchange it for root beer that Kris makes.c.The highest price of pizza in terms of root beer that will make bothroommates better off is 2/3 gallons of root beer. If the price were higherthan that, then Kris would prefer making her own pizza (at an opportunitycost of 2/3 gallons of root beer) rather than trading for pizza that Pat makes.The lowest price of pizza in terms of root beer that will make bothroommates better off is 1/2 gallon of root beer. If the price were lower thanthat, then Pat would prefer making her own root beer (she can make 1/2gallon of root beer instead of making a pizza) rather than trading for rootbeer that Kris makes.5. a.Since a Canadian worker can make either two cars a year or 30 bushels ofwheat, the opportunity cost of a car is 15 bushels of wheat. Similarly, theopportunity cost of a bushel of wheat is 1/15 of a car. The opportunitycosts are the reciprocals of each other.b.See Figure 3-4. If all 10 million workers produce two cars each, theyproduce a total of 20 million cars, which is the vertical intercept of theproduction possibilities frontier. If all 10 million workers produce 30 bushelsof wheat each, they produce a total of 300 million bushels, which is thehorizontal intercept of the production possibilities frontier. Since thetradeoff between cars and wheat is always the same, the productionpossibilities frontier is a straight line.If Canada chooses to consume 10 million cars, it will need 5 million workersdevoted to car production. That leaves 5 million workers to produce wheat,who will produce a total of 150 million bushels (5 million workers times 30bushels per worker). This is shown as point A on Figure 3-4.c.If the United States buys 10 million cars from Canada and Canada continuesto consume 10 million cars, then Canada will need to produce a total of 20million cars. So Canada will be producing at the vertical intercept of theproduction possibilities frontier. But if Canada gets 20 bushels of wheat percar, it will be able to consume 200 million bushels of wheat, along with the10 million cars. This is shown as point B in the figure. Canada should acceptthe deal because it gets the same number of cars and 50 million morebushes of wheat.Figure 3-46.Though the professor could do both writing and data collection faster than thestudent (that is, he has an absolute advantage in both), his time is limited. If theprofessor’s comparative advantage is in writing, it makes sense for him to pay astudent to collect the data, since that’s the student’s comparative advantage.7. a.English workers have an absolute advantage over Scottish workers inproducing scones, since English workers produce more scones per hour (50vs. 40). Scottish workers have an absolute advantage over English workersin producing sweaters, since Scottish workers produce more sweaters perhour (2 vs. 1). Comparative advantage runs the same way. Englishworkers, who have an opportunity cost of 1/50 sweaters per scone (1sweater per hour divided by 50 scones per hour), have a comparativeadvantage in scone production over Scottish workers, who have anopportunity cost of 1/20 sweater per scone (2 sweaters per hour divided by40 scones per hour). Scottish workers, who have an opportunity cost of 20scones per sweater (40 scones per hour divided by 2 sweaters per hour),have a comparative advantage in sweater production over English workers,who have an opportunity cost of 50 scones per sweater (50 scones per hourdivided by 1 sweater per hour).b.If England and Scotland decide to trade, Scotland will produce sweaters andtrade them for scones produced in England. A trade with a price between20 and 50 scones per sweater will benefit both countries, as they’ll be gettingthe traded good at a lower price than their opportunity cost of producing thegood in their own country.c.Even if a Scottish worker produced just one sweater per hour, the countrieswould still gain from trade, because Scotland would still have a comparativeadvantage in producing sweaters. Its opportunity cost for sweaters wouldbe higher than before (40 scones per sweater, instead of 20 scones persweater before). But there are still gains from trade since England has ahigher opportunity cost (50 scones per sweater).8. a.Technological advance lowers the opportunity cost of producing meat for thefarmer. The opportunity cost of producing a point of meat was 2 pounds ofpotatoes; it’s now 1/5 pounds of potatoes. Thus the farmer’s opportunitycost of producing potatoes is now 5 pounds of meat. Since the rancher’sopportunity cost of producing potatoes is 8 pounds of meat, the farmer stillhas a comparative advantage in producing potatoes and the rancher still hasa comparative advantage in producing meat.b.Now the farmer won’t be willing to trade a pound of potatoes for 3 pounds ofmeat because if he produced one less pound of potatoes, he could produce 5more pounds of meat. So the trade would be bad for the farmer, as hewould then be consuming inside his production possibilities frontier.c.The farmer and rancher would now be willing to trade one pound of potatoesfor an amount between 5 and 8 pounds of meat, with the potatoes beingproduced by the farmer and the meat being produced by the rancher.9. a.With no trade, one pair of white socks trades for one pair of red socks inBoston, since productivity is the same for the two types of socks. The pricein Chicago is 2 pairs of red socks per pair of white socks.b.Boston has an absolute advantage in the production of both types of socks,since a worker in Boston produces more (3 pairs of socks per hour) than aworker in Chicago (2 pairs of red socks per hour or 1 pair of white socks perhour).Chicago has a comparative advantage in producing red socks, since theopportunity cost of producing a pair of red socks in Chicago is 1/2 pair ofwhite socks, while the opportunity cost of producing a pair of red socks inBoston is 1 pair of white socks. Boston has a comparative advantage inproducing white socks, since the opportunity cost of producing a pair ofwhite socks in Boston is 1 pair of red socks, while the opportunity cost ofproducing a pair of white socks in Chicago is 2 pairs of red socks.c.If they trade socks, Boston will produce white socks for export, since it hasthe comparative advantage in white socks, while Chicago produces red socksfor export, which is Chicago’s comparative advantage.d.Trade can occur at any price between 1 and 2 pairs of red socks per pair ofwhite socks. At a price lower than 1 pair of red socks per pair of whitesocks, Boston will choose to produce its own red socks (at a cost of 1 pair ofred socks per pair of white socks) instead of buying them from Chicago. Ata price higher than 2 pairs of red socks per pair of white socks, Chicago willchoose to produce its own white socks (at a cost of 2 pairs of red socks perpair of white socks) instead of buying them from Boston.10. a.The cost of all goods is lower in Germany than in France in the sense that allgoods can be produced with fewer worker hours.b.The cost of any good for which France has a comparative advantage is lowerin France than in Germany. Though Germany produces all goods with lesslabor, that labor is more valuable. So the cost of production, in terms ofopportunity cost, will be lower in France for some goods.c.Trade between Germany and France will benefit both countries. For eachgood in which it has a comparative advantage, each country should producemore goods than it consumes, trading the rest to the other country. Totalconsumption will be higher in both countries as a result.11. a.True; two countries can achieve gains from trade even if one of the countrieshas an absolute advantage in the production of all goods. All that’snecessary is that each country have a comparative advantage in some good.b.False; it is not true that some people have a comparative advantage ineverything they do. In fact, no one can have a comparative advantage ineverything. Comparative advantage reflects the opportunity cost of onegood or activity in terms of another. If you have a comparative advantagein one thing, you must have a comparative disadvantage in the other thing.c.False; it is not true that if a trade is good for one person, it can’t be good forthe other one. Trades can and do benefit both sides especially tradesbased on comparative advantage. If both sides didn’t benefit, trades wouldnever occur.。

商务英语阅读chapter3练习答案

10
• In a time when customers change constantly and rapidly in their needs, only companies who are quick to respond can survive and succeed in the end.
Exercise 4
1
• Experts have attributed the main cause of the company’s poor performance to its poor HR functions, especially the appointment if the senior management.
9
• With the efforts of these university students, it was brought to light that this world-famous multinational had established some sweat factories in China.
• 熟悉原则其实非常简单易懂:熟悉的食物总是比那些陌生的事物更能激起我们的信心。
• 熟悉机制在广告界中一直备受忽略。
• 但是，在现实生活中，当一个消费者在面对两个产品并对他们的物理特性一无所知的情况下，几乎肯定会选择较为熟悉的那一个品牌。
• 因此，一个广告，哪怕是那些乏善可陈的广告---只要提到了产品名称，就会有助于该产品的销售，这种广告的作用就在于它建立了品牌意识，并在消费者心中树立了上面所讲的最低程度的信心。
4
• After financial scandals, many companies can only resort to charity activities to improve their corporate image.

chapter3-1

③高聚物聚集态
晶态
非极性
因此高分子溶解比小分子要复杂得多。
极性
聚合物溶解过程的特点
a 溶解过程缓慢，且先溶胀再溶解 b 非晶态聚合物比结晶聚合物易于溶解
c 交联聚合物只溶胀，不溶解
18
3.1.1 溶解过程 3.1.1.1非晶态聚合物的溶胀和溶解

线形非晶态聚合物溶解过程分两步进行：首先溶胀(溶剂分子和高分子的某些链段混合），然后溶解（溶剂分子和整个高分子链的混合）。溶解度与分子量有关。通常分子量大的，溶解度小；分子量小的，溶解度大。提高温度一般可以增加其溶解度；降低温度则减小其溶解度。
第3章高分子溶液

高分子溶液：聚合物以分子状态分散在溶剂中所形成的均相体系。高分子溶液的分类： (A)稀溶液：浓度＜ 1%，粘度小且稳定性好，处于热力学平衡态的真溶液； (B)高分子浓溶液：一般浓度＞ 5% ； (C)高分子的亚浓溶液对于稀溶液，随着浓度的提高，孤立存在的无规线团分子开始相互接触，继而交叠，形成所谓的“亚浓溶液”。
例：聚丙烯腈
混合溶剂的选择：
单一组分的溶剂对高聚物的溶解效果不好，可以考虑使用混合溶剂： δ混＝δ1Φ1＋δ2Φ2 Φ1，Φ2：两种纯溶剂的体积分数； δ1, δ2：两种纯溶剂的溶度参数。
(三) “高分子－溶剂相互作用参数 1小于 1/2 ” 原则
高分子－溶剂相互作用参数 1反映高分子与溶剂混合时相互作用能的变化。
1 ＜ 1/2 聚合物在溶剂中溶解 1 =1/2 θ溶液状态
1 2
1 ＞ 1/2 聚合物在溶剂中不溶解, 或者会从溶液中沉淀析出
小结

1名词：高分子溶液；溶度参数。 2掌握聚合物溶解过程的特点，以及典型的几种聚合物的良溶剂。 3掌握溶度参数的测定方法以及选择混合溶剂溶解聚合物的计算。 4熟练掌握对聚合物溶解能力的判定原则。

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Chapter3习题集及答案Chapter 3 Foreign Currency Futures3.1 Multiple Choice and True/False Questions1) Financial derivatives are powerful tools that can be used by management for purposes ofA) speculation.B) hedging.C) arbitrage.D) A, B and C above.Answer: D2) A foreign currency ________ contract calls for the future delivery of a standard amount of foreign exchange at a fixed time, place, and price.A) futuresB) forwardC) optionD) swapAnswer: A3) Currency futures contracts have become standard fare and trade readily in the world money centers. Answer: TRUE4) The major difference between currency futures andforward contracts is that futures contracts are standardized for ease of trading on an exchange market whereas forward contracts are specialized and tailoredto meet the needs of clients.Answer: TRUE5) Which of the following is NOT a contract specification for currency futures trading on an organized exchange?A) size of the contractB) maturity dateC) last trading dayD) fixed gainsAnswer: D6) About ________ of all futures contracts are settled by physical delivery of foreign exchange between buyer and seller.A) 0%B) 5%C) 50%D) 95%Answer: B7) Futures contracts require that the purchaser deposit an initial sum as collateral. This deposit is called aA) collateralized deposit.B) marked market sum.C) margin.D) settlement.Answer: C8) A speculator in the futures market wishing to lock ina price at which they could ________ a foreign currency will ________ a futures contract.A) buy; sellB) sell; buyC) buy; buyD) none of the aboveAnswer: C9) A speculator that has ________ a futures contract has taken a ________ position.A) sold; longB) purchased; shortC) sold; shortD) purchased; soldAnswer: C10) Peter Simpson expects that the U.K. pound will cost $1.62/￡in six months. A 6-month currency futures contract is available today at a rate of $1.63/￡. If Peter was to speculate in the currency futures market, and his expectations are correct, which of the following strategies would earn him a profit?A) Sell a pound currency futures contract.B) Buy a pound currency futures contract.C) Sell pounds today.D) Sell pounds in six months.Answer: A11) Jack Hemmings bought a 3-month British pound futures contract for $1.6200/￡only to see the dollar appreciate to a value of $1.6118 at which time he sold the pound futures. If each pound futures contract is for an amount of ￡62,500, how much money did Jack gain or lose from his speculation with pound futures?A) $512.50 lossB) $512.50 gainC) ￡512.50 lossD) ￡512.50 gainAnswer: A12) Which of the following statements regarding currency futures contracts and forward contracts is true?A) A futures contract is a standardized amount per currency whereas the forward contact is for any size desired.B) A futures contract is for a fixed maturity whereas the forward contract is for any maturity you like up to one year.C) Futures contracts trade on organized exchanges whereas forwards take place between individuals and banks with other banks via telecom linkages.D) All of the above are true.Answer: D13) Which of the following is a difference between a currency futures contract and a forward contract?A) The futures contract is marked to market daily whereas the forward contract is only due to be settled at maturity.B) The counterparty to the futures participant is unknown with the clearinghouse stepping into each transaction whereas the forward contract participantsare in direct contact setting the forward specifications.C) A single sales commission covers both the purchase and sale of a futures contract whereas there is no specific sales commission with a forward contract because banks earn a profit through the bid-ask spread.D) All of the above are true.Answer: D14) As a general statement, it is safe to say that businesses generally use the ________ for foreign currency forward contracts, and individuals and financial institutions typically use the ________for foreign currency futures contracts.A) exchange markets; over-the-counterB) over-the-counter; exchange marketsC) private; government sponsoredD) government sponsored; privateAnswer: B15) All exchange-traded futures are settled through a clearing house but over-the-counter forwards are not and are thus subject to greater ________ risk.A) exchange rateB) countryC) counterpartyD) none of the aboveAnswer: C16) When reading the futures quotation in the financial section of the newspaper, the column heading indicating the number of contracts outstanding is called ________.A) contracts outstandingB) settleC) open interestD) short positionsAnswer: CTable 3.1Use the below mentioned table to answer following question(s). December 17, 2009, British Pound futures Prices for 2010 (US dollars per pound, 62,500 pound contracts).Maturity Open High Low Change Settle Volume March 10 1.6315 1.6333 1.6071 -0.0155 1.6146 127,234 June 10 1.6315 1.6323 1.6065 -0.0155 1.6137 14517)Refer to Table 3.1. What was the contract price ofthe British pound, if you need to lock the value of GBP for your GBP receivables in 3-month period?A) $1.6146/￡B) ￡1.6146/$C) $1.6315/￡D) ￡1.6315/$Answer: A18) Refer to Table 3.1. The price of ________ making you taking a short position to sell two pounds futures contracts have maturity date in June 10, 2010 has a total contract value of ________.A) ￡1.6137/$, ￡201,712.50B) $1.6137/￡, $201,712.50C) $1.6146/￡, $100,912.50D) ￡1.6146/$, $100,912.50Answer: B19) Refer to Table 3.1 and question 19. If the spot exchange rate of British pound proves to be $1.6128/￡in June 10, 2010, what is your gain or loss for your short position?A) $112.50 gainB) $112.50 lossC) $56.25 gainD) $56.25 lossAnswer: A20) Andrea Lee is a currency speculator who enjoys "betting" on changes in the foreign currency exchange market. Currently the spot price for the Japanese yen is ￥90.870/$ and the 6-month futures contract price is ￥90.530/$. Andrea thinks the yen will move to ￥90.120/$ in the next six months. Andrea should ________ at the futures price to profit from changing currency values.A) buy yenB) buy dollarsC) sell yenD) There is not enough information to answer this question.Answer: A3.2 Essay Questions1) Why are foreign currency futures contracts more popular with individuals and banks while foreign currency forwards are more popular with businesses? Answer: Foreign currency futures are standardizedcontracts that lendthemselves well to speculation purposes but less so for hedging purposes. The standardized nature of the futures contract makes it easy to trade futures and to make bets about general changes in the value of currencies. Forward contracts are better for hedging in that they are tailored to meet the specific needs of the client, typically a business, and can be quite useful in reducing exchange rate risk. Banks are involved in the foreign currency futures market in part to offset positions that they may have taken in the forward markets as dealers.2) How do currency forward and futures contracts differ with respect to maturity, settlement, and the size and timing of cash flows?Answer: see p36-37, Table 3.73) What is the primary role of the exchange clearinghouse?Answer: see p14-15※4) Draw and explain the payoff profile associated with a currency futures contract.Answer: refer to chapter 8。