Ch01 A Preview of Business Statistics
商品说明书：级别2商业统计（VRQ）ASE20096卷
*P54282A0124*Turn over Instructions• Useblack ink or ball-point pen – pencil can only be used for graphs, charts, diagrams, etc.• Fill in the boxesat the top of this page with your name, candidate number, centre code and your candidate ID number.• Answerall questions.• Answer the questions in the spaces provided – there may be more space than you need.• Answers should be given to an appropriate degree of accuracy.Information• The total mark for this paper is 100.• The marks for each question are shown in brackets – use this as a guide as to how much time to spend on each question.• A formulae sheet is provided at the front of this question paper.• Calculators may be used.Advice• Read each question carefully before you start to answer it.• Try to answer every question.• You are advised to show your workings.• Check your answers if you have time at the end.Certificate in Business Statistics (VRQ)Level 2ASE20096Monday 20 November 2017Time: 2 hours 30 minutesComplete the details below in block capitals.Candidate nameCentre Code Candidate NumberCandidate ID NumberTotal MarksP54282A©2017 Pearson Education Ltd.1/1/1/1/1/1Paper ReferencePearson LCCIYou must have:HB pencil, eraser*P54282A0224*2*P54282A0324*Turn over3BLANK PAGE*P54282A0424*4Answer ALL questions. Write your answers in the spaces provided.1 AMG, a market gardening company, wishes to investigate the relationship betweenthe total weight of tomatoes produced by a tomato plant (y kilograms) and theamount of fertiliser used (x grams).An experiment was conducted by applying known amounts of fertiliser to similarplants and weighing the resulting yields.Here are the results obtained from 10 tomato plants.Weight of fertiliser (x grams)Yield of tomatoes (y kilograms)0 4.012 4.704 5.026 4.848 5.3810 5.6112 5.4714 5.8016 5.9018 5.95(a) State which of the two variables is the response variable.You must give a reason for your answer.(2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................*P54282A0524*Turn over5(b) Plot these data on a scatter diagram on the grid below.(3)The managing director of AMG says ‘The scatter diagram shows positive correlation’.(c) Explain, in the context of the question, what this means.(1)............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................*P54282A0624*6When the data in the table are entered into a computer spreadsheet the following summary statistics are obtained.∑ x= 90 ∑ y= 52.68 ∑ xy= 506 ∑ x2 = 1140(d) Calculate the equation of the least squares regression line for yield of tomatoeson weight of fertiliser.(6).................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 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....................................................................................................................................................................................................................................................................................(e) Explain what the intercept and the gradient of the least squares regression linetell AMG.(3)Intercept .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 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Gradient .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................*P54282A0724*Turn over7(f) Estimate, using your equation in part (d), the weight of fertiliser needed for atomato plant to produce a yield of 5.20 kg.(3)........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................The correlation coefficient between weight of fertiliser and yield is 0.94(g) Discuss the reliability of your estimate in part (f).(2)................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(Total for Question 1 = 20 marks)*P54282A0824*82 The table shows the bonuses paid (x , $000) to a sample of 100 employees of LCV plc,an insurance company, in 2016Bonus paid (x , $000)Number of employees Total bonus payments x 4 7 14 4 < x 8 12 72 8 < x 9 20 170 9 < x 10 26 247 10 < x 16 29 37716 < x 246120(a) Calculate an estimate for the mean bonus.(3)....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(b) Calculate an estimate for the standard deviation.(4)........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................*P54282A0924*Turn over9(c) Give a reason why the standard deviation might be a better measure of spread touse in this case rather than the quartile deviation.(1)................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(d) Using your answers from parts (a) and (b), calculate the coefficient of variation forthese data.(2)....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(e) Explain what your answer to part (d) measures.(1)................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................*P54282A01024*10 The table of bonuses paid from page 8 is shown again here.Bonus paid (x, $000)Number of employees Total bonus paymentsx 4 7 144 < x 8 12 728 < x 9 20 1709 < x 10 26 24710 < x 16 29 37716 < x 24 6 120(f) Use these data to construct a Lorenz curve.(7)(g) Describe what the diagram shows about the distribution of bonuses paid in 2016(2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................(Total for Question 2 = 20 marks)BLANK PAGEassurance manager has to test the batteries regularly to ensure that they satisfyquality standards.In a day, the factory produces 5000 batteries and each battery has a unique barcode.The quality assurance manager intends to select a sample of 120 of these batteries.(a) Give two reasons why the quality assurance manager would take a sample ratherthan a census of the batteries produced in a day.(2)1 ............................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................2 ............................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................(b) Suggest a suitable sampling frame for the quality assurance manager to use.(1) .................................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................The quality assurance manager chooses to use simple random sampling to select the120 batteries.(c) Describe how the quality assurance manager would do this.(3) .................................................................................................................................................................................................................................................................................... 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.................................................................................................................................................................................................................................................................................... ........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................(e) Estimate the modal time from the histogram.(3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................(f) Estimate the percentage of these batteries that last less than 430 minutes.(3) 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....................................................................................................................................................................................................................................................................................One of these batteries is selected at random.(g) Calculate the probability that this battery lasted longer than 525 minutes.(2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... ....................................................................................................................................................................................................................................................................................(Total for Question 3 = 20 marks)。
商务统计学课件英文版BSFC7e-CH01
Chapter 1, Slide 5
Collecting Data Correctly Is A Critical
Task
DCOVA
▪ Need to avoid data flawed by biases, ambiguities, or other types of errors.
▪ Results from flawed data will be suspect or in error.
Chapter 1, Slide 2
Classifying Variables By Type
DCOVA
▪ Categorical (qualitative) variables take categories as their values such as “yes”, “no”, or “blue”, “brown”, “green”.
Copyright © 2016, 2013, 2010 Pearson Education, Inc.
Chapter 1, Slide 7
Establishing A Business Objective
Focuses Data Collection
Examples Of Business Objectives:
People being surveyed to determine their satisfaction with a recent product or service experience.
Copyright © 2016, 2013, 2010 Pearson Education, Inc.
Chapter 1, Slide 12
Examples of Survey Data
应用统计学英文课件 Business Statistics Ch02 Presenting Data in Tables and Charts
Chap 2-14
Organizing Categorical Data: Pareto Chart
A large injection-molding company manufacturing plastic components used in computer keyboards.
Data in Table 2.3 consist of all computer keyboards with defects produced during a three-month period.
shown in descending order of frequency A cumulative polygon is shown in the same
graph Used to separate the “vital few” from the “trivial
many”
Business Statistics: A First Course, 5e © 2009 Prentice-Hall, Inc.
Chap 2-6
Organizing Categorical Data: Summary Table
A summary table indicates the frequency, amount, or percentage of items in a set of categories so that you can see differences between categories.
17%
In person at branch
41%
Internet
24%
Business Statistics: A First Course, 5e © 2009 Prentice-Hall, Inc.
business statistics_ppt_ch01
Basic Business Statistics, 11e 2009 Prentice-Hall, Inc..
Chap 1-6
Descriptive Statistics
Collect data
e.g., Survey
Present data
e.g., Tables and graphs
Characterize data
In this chapter you learn: How Statistics is used in business The sources of data used in business The types of data used in business The basics of Microsoft Excel The basics of Minitab
Analyzing census data Examining data from print journals or data published on the internet.
Basic Business Statistics, 11e 2009 Prentice-Hall, Inc..
Chap 1-13
Basic Business Statistics, 11e 2009 Prentice-Hall, Inc..
Chap 1-2
Why Learn Statistics?
So you are able to make better sense of the ubiquitous use of numbers: Business memos Business research Technical reports Technical journals Newspaper articles Magazine articles
Data Mining - Concepts and Techniques CH01
We are drowning in data, but starving for knowledge! Solution: Data warehousing and data mining
Data warehousing and on-line analytical processing Miing interesting knowledge (rules, regularities, patterns,
3
Chapter 1. Introduction
Motivation: Why data mining? What is data mining? Data Mining: On what kind of data? Data mining functionality Are all the patterns interesting? Classification of data mining systems Major issues in data mining
Other Applications
Text mining (news group, email, documents) and Web mining
Stream data mining
DNA and bio-data analysis
September 14, 2019
Data Mining: Concepts and Techniques
multidimensional summary reports
statistical summary information (data central tendency and variation)
《Business statistic》复习参考(第一章至第八章)
《Business Statistic》中国人民大学出版社英文版第五版chapter1~8复习参考Part1名词解释1、Statistics is a method of extracting useful information from a set of numerical data in orderto make a more effective and informed decision.2、Descriptive Statistics：These are statistical methods of organizing, summarizing andpresenting numerical data in convenient forms such as graphs, charts and tables.3、Inferential statistics is defined as statistical methods used for drawing conclusions about apopulation based on samples.4、Primary data is obtained first hand.5、Secondary data already exists or has been previously collected such as company accounts, orsales figures.6、Mean: The arithmetic average and the most common measure ofaaaaaaa central tendency.①All values are included in computing the mean.②A set of data has a unique mean ③Themean is affected by unusually large or small data points (outliers / extreme values).7、Mode: The most frequent data, or data corresponding to the highest frequency. ①Mode isnot affected by extreme values. ②There may not be a mode. ③There may be several modes. ④Used for either numerical or categorical data.8、Median is the value that splits a ranked set of data into two equal parts. ①Median is notaffected by extremely large or small values and is therefore a valuable measure of central tendency when such values occur.9、Standard Deviation: ①A measure of the variation of data from the mean. ②The mostcommonly used measure of variation. ③Represented by the symbol ‘s’. ④Shows how the data is distributed around the mean.10、Probability is the chance of an occurrence of an event. ①Probability of an eventalways lies between 0 and 1. ②The sum of the probabilities of every possible outcome or event is 1. ③The probability of the complement A’ is given by 1-P(A).11、Properties of Normal distribution：①Continuous random variable. ②‘Bell-shaped’ &symmetrical. ③Mean, median, mode are equal ④Area under the curve is 1.12、The Central Limited Theorem：①If the population followed normal distribution, thesampling distribution of mean is followed normal distribution. ②If the population do not followed normal distribution, but the sample size is larger than 30, the sampling distribution of mean is followed normal distribution.Part2选择题Topic 1 - Introduction to Business Statistics & Data CollectionQ1. The universe or totality of items or things under consideration is called:a. a sample.b. a population.c. a parameter.d.none of the above.Q2. Those methods involving the collection, presentation, and characterization of a set of data in order to properly describe the various features of that set of data are called:a.inferential statistics.b.total quality management.c.sampling.d.descriptive statistics.Q3. The portion of the universe that has been selected for analysis is called:a. a sample.b. a frame.c. a parameter.d. a statistic.Q4. A summary measure that is computed to describe a numerical characteristic from only a sample of the population is called:a. a parameter.b. a census.c. a statistic.d.the scientific method.Q5. A summary measure that is computed to describe a characteristic of an entire population is called:a. a parameter.b. a census.c. a statistic.d.total quality management.Q6. The process of using sample statistics to draw conclusions about population parameters is called:a.inferential statistics.b.experimentation.c.primary sources.d.descriptive statistics.Q7. Which of the four methods of data collection is involved when a person retrieves data from an online databasea.published sources.b.experimentation.c.surveying.d.observation.Q8. Which of the four methods of data collection is involved when people are asked to complete a questionnairea.published sources.b.experimentation.c.surveying.d.observation.Q9. Which of the four methods of data collection is involved when a person records the use of the Los Angeles freeway systema.published sources.b.experimentation.c.surveying.d.observation.Q10. A focus group is an example of which of the four methods of data collectiona.published sources.b.experimentation.c.surveying.d.observation.Q11. Which of the following is true about response ratesa.The longer the questionnaire, the lower the rate.b.Mail surveys usually produce lower response rates than personal interviews or telephonesurveys.c.Question wording can affect a response rate.d. d. All of the above.Q12. Which of the following is a reason that a manager needs to know about statisticsa.To know how to properly present and describe information.b.To know how to draw conclusions about the population based on sample information.c.To know how to improve processes.d.All of the above.Scenario 1-1Questions 13-15 refer to this scenario:An insurance company evaluates many variables about a person before deciding on an appropriate rate for automobile insurance. Some of these variables can be classified as categorical, discrete and numerical, or continuous and numerical.Q13. Referring to Scenario 1-1 (above), the number of claims a person has made in the last three years is what type of variablea.Categorical.b.Discrete and numerical.c.Continuous and numerical.d.None of the above.Q14. Referring to Scenario 1-1 (above), a person's age is what type of variablea.Categorical.b.Discrete and numerical.c.Continuous and numerical.d.None of the above.Q15. Referring to Scenario 1-1 (above), a person's gender is what type of variablea.Categorical.b.Discrete and numerical.c.Continuous and numerical.d.None of the above.Q16. Which of the following can be reduced by proper interviewer traininga.Sampling error.b.Measurement error.c.Coverage error.d.Nonresponse error.Scenario 1-2Questions 17-19 refer to this scenario:Mediterranean fruit flies were discovered in California a few years ago and badly damaged the oranges grown in that state. Suppose the manager of a large farm wanted to study the impact of the fruit flies on the orange crops on a daily basis over a 6-week period. On each day a random sample of orange trees was selected from within a random sample of acres. The daily average number of damaged oranges per tree and the proportion of trees having damaged oranges were calculated.Q17. Referring to Scenario 1-2 (above), the two main measures calculated each day ., average number of damaged oranges per tree and proportion of trees having damaged oranges) are called _______.a.statistics.b.parameters.c.samples.d.populations.Q18. Referring to Scenario 1-2 (above), the two main measures calculated each day ., average number of damaged oranges per tree and proportion of trees having damaged oranges) may be used on a daily basis to estimate the respective true population _______.a.estimates.b.parameters.c.statistics.d.frame.Q19. Referring to Scenario 1-2 (above), in this study, drawing conclusions on any one day about the true population characteristics based on information obtained from the sample is called _______.a.evaluation.b.descriptive statistics.c.inferential statistics.d.survey.Scenario 1-3Questions 20 and 21 refer to this scenario:The Quality Assurance Department of a large urban hospital is attempting to monitor and evaluate patient satisfaction with hospital services. Prior to discharge, a random sample of patients is asked to fill out a questionnaire to rate such services as medical care, nursing, therapy, laboratory, food, and cleaning. The Quality Assurance Department prepares weekly reports that are presented at the Board of Directors meetings and extraordinary/atypical ratings are easy to flag.Q20. Referring to Scenario 1-3 (above), true population characteristics estimated from thesample results each week are called _____________.a.inferences.b.parameters.c.estimates.d.data.Q21. Referring to Scenario 1-3 (above), a listing of all hospitalised patients in this institution over a particular week would constitute the ________.a.sample.b.population.c.statistics.d.parameters.Scenario 1-4Questions 22-24 refer to this scenario:The following are the questions given to Sheila Drucker-Ferris in her college alumni association survey. Each variable can be classified as categorical or numerical, discrete or continuous.Q22. Referring to Scenario 1-4 (above), the data for the number of years since graduation is categorised as: __________________.a.numerical discrete.b.categorical.c.numerical continuous.d.none of the above.Q23. Referring to Scenario 1-4 (above), the data for the number of science majors is categorised as: ____________.a.categorical.b.numerical continuous.c.numerical discrete.d.none of the above.Q24. Referring to Scenario 1-4 (above), the data for tabulating the level of job satisfaction (High, Moderate, Low) is categorised as: _________.a.numerical continuous.b.categorical.c.numerical discrete.d.none of the above.Topic 2: Organising and Presenting dataQ1 The width of each bar in a histogram corresponds to the:a.boundaries of the classes.b.number of observations in the classes.c.midpoint of the classes.d.percentage of observations in the classes.Q2 When constructing charts, which of the following chart types is plotted at the class midpointsa.Frequency histograms.b.Percentage polygons.c.Cumulative relative frequency ogives.d.Relative frequency histograms.Q3 When polygons or histograms are constructed, which axis must show the true zero or "origin"a.The horizontal axis.b.The vertical axis.c.Both the horizontal and vertical axes.d.Neither the horizontal nor the vertical axis.Q4 To determine the appropriate width of each class interval in a grouped frequency distribution, we:a.divide the range of the data by the number of desired class intervals.b.divide the number of desired class intervals by the range of the datac.take the square root of the number of observations.d.take the square of the number of observations.Q5 When grouping data into classes it is recommended that we have:a.less than 5 classes.b.between 5 and 15 classes.c.more than 15 classes.d.between 10 and 30 classes.Q6 Which of the following charts would give you information regarding the number of observations "up to and including" a given groupa.Frequency histograms.b.Polygons.c.Percentage polygons.d.Cumulative relative frequency ogives.Q7 Another name for an "ogive" is a:a.frequency histogram.b.polygon.c.percentage polygon.d.cumulative percentage polygon.Q8 In analyzing categorical data, the following graphical device is NOT appropriate:a.bar chart.b.Pareto diagram.c.stem and leaf display.d.pie chart.Table 2The opinions of a sample of 200 people broken down by gender about the latest congressionalQ9 Table 2 (above) contains the opinions of a sample of 200 people broken down by gender about the latest congressional plan to eliminate anti-trust exemptions for professional baseball. Referring to Table 2, the number of people who are neutral to the plan is _______.a.36b.54c.90d.200Q10 Referring to Table 2, the number of males who are against the plan is _______.a.12b.48c.60d.96Q11 Referring to Table 2, the percentage of males among those who are for the plan is ______.a.%b.24%c.25%d.76%Q12 Referring to Table 2, the percentage who are against the plan among the females is _______.a.%b.20%c.30%d.52%Topic 3: Numerical Descriptive StatisticsQ1 Which measure of central tendency can be used for both numerical and categorical variablesa.Mean.b.Median.c.Mode.d.Quartiles.Q2 Which of the following statistics is not a measure of central tendencya.Mean.b.Median.c.Mode.d.Q3.Q3 Which of the following statements about the median is NOT truea.It is more affected by extreme values than the mean.b.It is a measure of central tendency.c.It is equal to Q2.d.It is equal to the mode in bell-shaped distributions.Q4 The value in a data set that appears most frequently is called:a.the median.b.the mode.c.the mean.d.the variance.Q5 In a perfectly symmetrical distribution:a.the mean equals the median.b.the median equals the mode.c.the mean equals the mode.d.All of the above.Q6 When extreme values are present in a set of data, which of the following descriptive summary measures are most appropriatea.CV and range.b.Mean and standard deviation.c.Median and interquartile range.d.Mode and variance.Q7 The smaller the spread of scores around the mean:a.the smaller the interquartile range.b.the smaller the standard deviation.c.the smaller the coefficient of variation.d.All the above.Q8 In a right-skewed distribution:a.the median equals the mean.b.the mean is less than the median.c.the mean is greater than the median.d.the mean is less than the mode.a.b.c.d.Q10 Referring to Table 3 (above), the median carbohydrate amount in the cereal is ________ grams.a.19b.20c.21d.Q11 Referring to Table 3 (above), the 1st quartile of the carbohydrate amounts is ________ grams.a.15b.20c.21d.25Q12 Referring to Table 3 (above), the range in the carbohydrate amounts is ________ grams.a.16b.18c.20d.21Topic 4: Basics probability and discrete probability distributionsInformation A, needed to answer Questions 1 to 2The Health and Safety committee in a large retail firm is examining the relationship between the number of days of sick leave an employee takes and whether an employee works on the day shift (D) or night shift (N). The committee looks at a sample of 50 employees and notes which shift they work on and whether the number of days of sick leave they take in a year is less than 6 daysQ1 Use Information A to answer this question. Which of the following statements about the values in the table of probabilities is not correcta.The probability of an employee taking 6 or more days of sick leave P(M) isb.The probability that an employee is on the Night Shift (N) and takes less than 6 days ofleave (L), is called a conditional probability P(N | L) =c.If you know that an employee is on day shift (D) then the probability that they will takeless than 6 days of leave (L) is the conditional probability P(L | D) =d.The probability that an employee works Day Shift (D) or takes 6 or more days of leave (M)is found using the addition rule to be P(D or M) =e.They are all correctQ2 The analyst wishes to use the Probabilities table from Information A to determine whether the work shift variable and the number of days of sick leave variable are or are not independent variables. Which of the following statements about the work shift and the number of days of sick leave variables is correcta.These variables are independent because the marginal probabilities such as P(L) are thesame as the conditional probabilities P(L | D)b.These variables are not independent because the marginal probability P(L) is differentfrom the conditional probability P(N | L)c.These variables are not independent because the joint probabilities such as P(L and N)are equal to the product of the probabilities P(L).P(N).d.These variables are dependent because the marginal probabilities such as P(L) are equalto the conditional probability P(L | N)e.None of the aboveInformation B, needed to answer Question 3Suppose the manager of a home ware retailer decides in a 5-minute period no more than 4 customers can arrive at a counter. Using past records he obtains the following probabilitythe following is the correct pair of values for the mean, the variance or standard deviation of the number of arrivals at the counter.a.Mean mu = 2 and variance sigma-squared =b.Mean mu = and variance sigma-squared =c.Mean mu = 2 and standard deviation sigma =d.Mean mu = and variance sigma-squared =e.None of the aboveInformation C, needed to answer Questions 4-6The section manager in an insurance company is interested in evaluating how well staff at the inquiry counter handle customer complaints. She interviews a sample of n = 6 customers who have made complaints and asks each of them whether staff had handled their complaints well. Each interview is called a trial. If a customer says their complaint was handled well this is called a success. She thinks that as long as these people are interviewed independently of each other then the number of people who say their complaint was handled well is a random variable with a Binomial probability distribution. The section manager thinks that the probability that a customers complaint will be handled well is p = .Q4 Use Information C to answer this question. A total of n = 6 people are interviewed independently of each other. Which of the following statements about the probability that 5 out of the 6 complaints will be handled well is correcta.less thanb.between andc.more thand.between ande.None of the aboveQ5 Using Information C, which of the following statements about the probability that 4 or less of the 6 complaints will be handled well is correcta.less thanb.more thanc.between andd.between ande.None of the aboveQ6 Suppose the section manager from Information C is interested in the measures of central tendency and variation for the number of complaints which are handled well. Which of the following sets of values, where values are rounded to 3 decimal places, is the correct set of valuesa.Mean mu = and variance sigma-squared =b.Mean mu = and variance sigma-squared =c.Mean mu = and variance sigma-squared =d.Mean mu = and standard deviation sigma =e.None of the aboveInformation D, needed to answer Questions 7-9The manager of a large retailer thinks that one reason why staff at the complaints counter fail to handle customer complaints well is that not enough staff are allocated to this counter. Past experience has shown that the number of customers who arrive at this counter has a Poisson distribution where the average number who arrive each hour is 36. He decides to look at how many customers are likely to arrive at the complaints counter during a 5-minute period.Q7 Use Information D to answer this question. Which of the following statements concerning the probability that exactly 2 customers will arrive at the counter in a 5-minute period is correcta.less thanb.between andc.between andd.more thane.None of the aboveQ8 Use Information D to answer this question. Which of the following statements concerning the probability that 3 or more customers will arrive at a counter in a 5-minute period is correcta.between andb.less thanc.more thand.between ande.None of the aboveQ9 The section manager from Information D is interested in the mean and variance of the number of customers who arrive during a 1 hour period. Which of the following is the correct set of values for these two measuresa.Mean mu = 3 and variance sigma-squared = 3b.Mean mu = 36 and standard deviation sigma =c.Mean mu = 30 and variance sigma-squared = 30d.Mean mu = 36 and standard deviation sigma = 6e.None of the aboveTopic 5: Normal probability distribution & sampling distributionQ1 Which of the following is not a property of the normal distributiona.It is bell-shaped.b.It is slightly skewed left.c.Its measures of central tendency are all identical.d.Its range is from negative infinity to positive infinity.Q2 The area under the standardized normal curve from 0 to would be:a.the same as the area from 0 to .b.equal to .c.found by using Table in your textbook.d.all of the above.Q3 Which of the following about the normal distribution is not truea.Theoretically, the mean, median, and mode are the same.b.About two-thirds of the observations fall within ± 1 standard deviation from the mean.c.It is a discrete probability distribution.d.Its parameters are the mean and standard deviation.Q4 In its standardized form, the normal distribution:a.has a mean of 0 and a standard deviation of 1.b.has a mean of 1 and a variance of 0.c.has a total area equal to .d.cannot be used to approximate discrete binomial probability distributions.Q5 In the standardized normal distribution, the probability that Z > 0 is _______.a.b.c.d.cannot be found without more informationQ6 The probability of obtaining a value greater than 110 in a normal distribution in which the mean is 100 and the standard deviation is 10 is ______________ the probability of obtaining a value greater than 650 in a normal distribution with a mean of 500 and a standard deviation of 100.a.less thanb.equal to.c.greater thand.It is unknown without more information.Q7 The probability of getting a Z score greater than is ________.a.close tob.c. a negative numberd.almost zeroQ8 For some positive value of Z, the probability that a standardized normal variable is between 0 and Z is . The value of Z isa.b.c.d.Q9 For some value of Z, the probability that a standardized normal variable is below Z is . The value of Z isa.b.c.d.Q10 Given that X is a normally distributed random variable with a mean of 50 and a standard deviation of 2, the probability that X is between 47 and 54 isa.b.c.d.Q11 For some positive value of X, the probability that a standardized normal variable is between 0 and + is . The value of X isa.b.c.d.Q12 The owner of a fish market determined that the average weight for a catfish is pounds with a standard deviation of pounds. A citation catfish should be one of the top 2 percent in weight. Assuming the weights of catfish are normally distributed, at what weight (in pounds) should the citation designation be establisheda.poundsb.poundsc.poundsd.poundsQ13 Which of the following is NOT a property of the arithmetic meana.It is unbiased.b.It is always equal to the population mean.c.Its average is equal to the population mean.d.Its variance becomes smaller when the sample size gets bigger.Q14 The sampling distribution of the mean is a distribution of:a.individual population values.b.individual sample values.c.statistics.d.parameters.Q15 The standard deviation of the sampling distribution of the mean is called the:a.standard error of the sample.b.standard error of the estimate.c.standard error of the mean.d.All of the aboveQ16 According to the central limit theorem, the sampling distribution of the mean can be approximated by the normal distribution:a.as the number of samples gets "large enough."b.as the sample size (number of observations) gets "large enough."c.as the size of the population standard deviation increases.d.as the size of the sample standard deviation decreases.Q17 For a sample size of n=10, the sampling distribution of the mean will be normally distributed:a.regardless of the population's distribution.b.if the shape of the population is symmetrical.c.if the variance of the mean is known.d.if the population is normally distributedTopic 6: EstimationQ1 The interval estimate using the t critical value is ________ than the interval estimate using the z critical value.a.Narrowerb.The same asc.Widerd.More powerfulQ2 To estimate the mean of a normal population with unknown standard deviation using a small sample, we use the ______ distribution.a.'t'b.'Z'c.samplingd.alphaQ3 If the population does not follow a normal distribution, then to use the t distribution to give a confidence interval estimate for the population mean, the sample size should be:a.at least 5b.at least 30c.at least 100d.less than 30Q4 The 'z' value or 't' value used in the confidence interval formula is called the:a.sigma valueb.critical valuec.alpha valued.none of the aboveQ5 The 'z' value that is used to construct a 90 percent confident interval is:a.b.c.d.Q6 The 'z' value that is used to construct a 95 percent confidence interval is:a.b.c.d.Q7 The sample size needed to construct a 90 percent confidence interval estimate for the population mean with sampling error ± when sigma is known to be 10 units is:a.9b.32c.75d.107Q8 The t critical value approaches the z critical value when:a.the sample size decreasesb.the sample size approaches infinityc.the confidence level increasesd.the sample is smallQ9 The t-critical value used when constructing a 99 percent confidence interval estimate with a sample of size 18 is:a.b.c.d.Q10 The t-value that would be used to construct a 90 percent confidence interval for the mean with a sample of size n 36 would be:a.b.c.d.Q11 The value of alpha (two tailed) for a 96 percent confidence interval would be: a.b.c.d.Q12 When using the t distribution for confidence interval estimates for the mean, the degrees of freedom value is:a.nb.n-1c.n-2d.n %2B 1Q13 You would interpret a 90 percent confidence interval for the population mean as:a.you can be 90 percent confident that you have selected a sample whose interval doesinclude the population meanb.if all possible samples are selected and CI's are calculated, 90 percent of those intervalswould include the true population meanc.90 percent of the population is in that intervald.both A and B are trueQ14 From a sample of 100 items, 30 were defective. A 95 percent confidence interval for the proportion of defectives in the population is:a.(.2, .4)b.(.21, .39)c.(.225, .375)d.(.236, .364)Q15 A confidence interval was used to estimate the proportion of statistics students that are male. A random sample of 70 statistics students generated the following 90 percent confidence interval: , . Using the information above, what size sample would be necessary if we wanted to estimate the true proportion to within ± using 95 percent confidencea.240b.450c.550d.150整理人：阿桤。
统计学CH01 英文教材
1.6
Example 2.6 Stats Anxiety
Are most of the marks clustered around the mean or are they more spread out? Range = Maximum – minimum = 92-53 = 39 Variance Standard deviation
Copyright © 2009 Cengage Learning
1.7
Example 2.6 Stats Anxiety
Are there many marks below 60 or above 80?
What proportion are A, B, C, D grades?
A graphical technique –histogram can provide us with this and other information
Chapter 2 introduces several graphical methods.
Copyright © 2009 Cengage Learning
1.10
Descriptive Statistics
Another form of descriptive statistics uses numerical techniques to summarize data. The mean and median are popular numerical techniques to describe the location of the data. The range, variance, and standard deviation measure the variability of the data Chapter 4 introduces several numerical statistical measures that describe different features of the data.
商务统计学ppt课件
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统计的应用领域
hydrology(水文学)
industry(工学)
linguistics(语言学)
literature(文学)
manpower planning(劳动力计划)
management science(管理科学)
marketing(市场营销学)
medical diagnosis(医学诊断)
称
离散变量：取有限个值 连续变量：可以取无穷多个值
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统计中的几个基本概念
总体（参数） 平均数 μ 标准差 σ 比例 Π
样本（统计量） ¯x s p
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几个常用的统计软件 （software）
典型的统计软件
SAS SPSS MINITAB STATISTICA EXCEL
所研究的全部元素的集合，其中的每一个元素称为 个体
分为有限总体和无限总体
有限总体的范围能够明确确定，且元素的数目是有限的 无限总体所包括的元素是无限的，不可数的
2、样本（sample）
从总体中抽取的一部分元素的集合 构成样本的元素的数目称为样本容量
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参数和统计量
1、参数（parameter）
商务统计学 Business Statistics
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参考书籍：
• 商务统计学 戴维.M.莱文等著 贾俊平改编
•
中国人民大学出版社
• 统计学原理 谢启南 主编 暨南大学出版社
• 统计学原理 贾俊平 中国人民大学出版社
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成绩评定方法
• 1.闭卷考试成绩（70%） • 2.平时作业、考勤和上机。（30%）
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Parameter
Types of Variables
• Qualitative Variables
– Attributes, categories
»Examples: male/female, registered to vote/not, ethnicity, eye color....
distance between elements. There is no absolute zero and multiples of measures are not meaningful.
distance between elements. There is an absolute zero and multiples of measures are meaningful.
© 2002 The Wadsworth Group
Problem 1.16, continued
• f) The number of students on campus who belong to a social fraternity or sorority • Quantitative, Discrete Variable
© 2002 The Wadsworth Group
• a) Whether you own • Qualitative Variable an RCA Colortrak – two levels: yes/no television set – no measurement • b) Your status as a • Qualitative Variable full-time or a part– two levels: full/part time student – no measurement • c) Number of people • Quantitative, Discrete who attended your Variable school’s graduation – a countable number last year – only whole numbers
© 2002 The Wadsworth Group
Problem 1.16
Problem 1.16, continued
• d) The price of • Quantitative, Discrete your most recent Variable haircut – a countable number
© 2002 The Wadsworth Group
Example: Types of Variables Problem 1.16
• For each of the following, indicate whether the appropriate variable would be qualitative or quantitative. If the variable is quantitative, indicate whether it would be discrete or continuous.
© 2002 The Wadsworth Group
Chapter 1 - Key Terms
• Collection, summarization, analysis, and reporting of numerical findings • Statistics - Two Usages
– A. The study of statistics – B. Statistics as reported sample measures
– only whole numbers
• e) Sam’s travel time from his dorm to the Student Union
• Quantitative, Continuous Variable
– any number – time is measured – can take on any value greater than zero
CHAPTER 1: A Preview of Business Statistics
to accompany
Introduction to Business Statistics
fourth edition, by Ronald M. Weiers
Presentation by Priscilla Chaffe-Stengel Donald N. Stengel
– a countable number – only whole numbers
© 2002 The Wadsworth Group
Scales of Measurement
• Nominal Scale - Labels represent various levels of a
categorical variable.
• Ordinal Scale - Labels represent an order that
indicates either preference or ranking.
• Interval Scale - Numerical labels indicate order and • Ratio Scale - Numerical labels indicate order and
• Quantitative Variables
– Discrete - usually take on integer values but can take
on fractions when variable allows - counts, how many – Continuous - can take on any value at any point along an interval - measurements, how much
»1. Descriptive »2. Inferential
© 2002 The Wadsworth Group
Chapter 1 - Key Terms InfLATION How Taken Measure Census SAMPLE Selected Subset Statistic
© 2002 The Wadsworth Group
Problem 1.20, continued
• a) nominal scale of measurement. • 1. Bill is going to college. 2. Bill will buy a Casio calculator. 3. Bill was a physics major. 4. Bill is a business major. 5. Bill was on the dean’s list.
© 2002 The Wadsworth Group
Example: Scales of Measurement Problem 1.20
• Bill scored 1200 on the Scholastic Aptitude Test and entered college as a physics major. As a freshman, he changed to business because he thought it was more interesting. Because he made the dean’s list last semester, his parents gave him $30 to buy a new Casio calculator. Identify at least one piece of information in the:
© 2002 The Wadsworth Group
Problem 1.20, continued
• b) ordinal scale of measurement • Bill is a freshman.
• c) interval scale of • Bill earned a 1200 on the measurement SAT.
• d) ratio scale of measurement
• Bill’s parents gave him $30.
© 2002 The Wadsworth Group