商务统计学试卷D优选稿
最新商务统计经典考试及答案

商务统计经典考试及答案答案2010.10.21一, 填空题(10×2.5 = 25分)1, 反映顺序变量数据的集中趋势的指标可以用(众 )数或( 中位 )数来测度。
2, 某房地产开发公司2003年售出的300套不同户形的情况如下(单位:套):户型两室一厅一卫三室两厅两卫四实两厅两卫五室两厅两卫套数 96 150 46 8公司2003年售出住房(户型)的众数为( 三室两厅两卫 )异众比为( 1-150/300 =0.5 )。
3,(典型)调查、重点调查和(抽样)调查、都属于非全面调查。
4,所列数字1/3 , 0.96, -0.56, 1.23, 3/2, 0, -2/5, 1 中,不可能是随机概率的是(-0.56, 1.23, 3/2, -2/5 ).5,抽样调查的误差来源主要有(登记性/非抽样)误差和(代表性/抽样)误差。
6,登记性误差从理论上讲是可以(消除)的,而(代表性/抽样)误差通常是无法消除的,但事先可以进行控制或计算。
7,某公司生产了一批新型号显像管,要检验这批显像管的寿命,只能采用(抽样)检验方法,测试样本的各显像管寿命,计算样本的显像管寿命的(平均值), 以此推断这批显像管平均寿命的点估计值。
8,随机变量Z 服从标准正态分布,则 Z ≥(-1.645 ) 的概率为95% ,Z≤(1.285) 的概率为 90% 。
9,总体为正态分布、方差σ2未知。
样本量n = 20、样本的平均值为χ、标准差为 S ,当置信水平为1-α时,总体均值μ的置信区间为(χ±tα/2 (20-1) S/√20 )。
10, 一种零件的标准长度5cm ,要检验某天生产的零件是否符合标准要求,建立的原假设和备择假设应为( H0:µ = 5,H1:µ≠ 5)二,单选题(将答案的英文字母填入括号内)(8×2。
5分=20分)1, ,在新修的马路两旁种植了绿化的树木,为了估计成活的比例,检查人员在马路一旁每隔 10 棵树检查一棵树的成活情况, 这种抽样方式是 ( B )。
商务统计选择答案.doc

Part One: Multiple Choices:1.The probability that a continuous random variable takes any specific valuea.is equal to zerob.is at least 0.5c.depends on the probability density functiond.is very close to 1.02. A normal distribution with a mean of 0 and a standard deviation of 1 is calleda. a probability density functionb.an ordinary normal curvec. a standard normal distributiond.none of these alternatives is correct3. A negative value of Z indicates thata.the number of standard deviations of an observation is to the right of the meanb.the number of standard deviations of an observation is to the left of the meanc. a mistake has been made in computations, since Z cannot be negatived.the data has a negative mean4.For a continuous random variable x, the probability density function f(x) representsa.the probability at a given value of xb.the area under the curve at xc.the area under the curve to the right of xd.the height of the function at x5.For the standard normal probability distribution, the area to the left of the mean isa.-0.5b.0.5c.any value between 0 to 1d. 1rger values of the standard deviation result in a normal curve that isa.shifted to the rightb.shifted to the leftc.narrower and more peakedd.wider and flatter7. A continuous probability distribution that is useful in describing the time, or space,between occurrences of an event is a(n)a.normal probability distributionb.uniform probability distributionc.exponential probability distributiond.Poisson probability distribution8.Consider a binomial probability experiment with n = 3 and p = 0.1. Then, the probabilityof x = 0 isa.0.0000b.0.0001c.0.001d.0.7299. A continuous random variable may assumea.all values in an interval or collection of intervalsb.only integer values in an interval or collection of intervalsc.only fractional values in an interval or collection of intervalsd.all the positive integer values in an interval10.The highest point of a normal curve occurs ata.one standard deviation to the right of the meanb.two standard deviations to the right of the meanc.approximately three standard deviations to the right of the meand.the meanExhibit 1The assembly time for a product is uniformly distributed between 6 to 10 minutes.11.Refer to Exhibit 1. The probability density function has what value in the interval between 6 and 10?a.0.25b. 4.00c. 5.00d.zero12.Refer to Exhibit 1. The probability of assembling the product between 7 to 9 minutes isa.zerob.0.50c.0.20d. 113.Refer to Exhibit 1. The probability of assembling the product in less than 6 minutes isa.zerob.0.50c.0.15d. 114.Refer to Exhibit 1. The probability of assembling the product in 7 minutes or more isa.0.25b.0.75c.zerod. 115.Refer to Exhibit 1. The expected assembly time (in minutes) isa.16b. 2c.8d. 416.Refer to Exhibit 1. The standard deviation of assembly time (in minutes) is approximatelya. 1.3333b. 1.1547c.0.1111d.0.577317.Center of a normal curve isa.always equal to zerob.is the mean of the distributionc.cannot be negatived.is the standard deviation18.The uniform, normal, and exponential distributions area.all continuous probability distributionsb.all discrete probability distributionsc.can be either continuous or discrete, depending on the datad.all the same distributions19.Which of the following is not a characteristic of the normal probability distribution?a.The mean, median, and the mode are equalb.The mean of the distribution can be negative, zero, or positivec.The distribution is symmetricald.The standard deviation must be 120.In a standard normal distribution, the range of values of z is froma.minus infinity to infinityb.-1 to 1c.0 to 1d.-3.09 to 3.0921.Parameters area.numerical characteristics of a sampleb.numerical characteristics of a populationc.the averages taken from a sampled.numerical characteristics of either a sample or a population22.How many simple random samples of size 3 can be selected from a population of size 7?a.7b.21c.35d.34323. A population consists of 500 elements. We want to draw a simple random sample of 50 elements from this population. On the first selection, the probability of an element being selected isa.0.100b.0.010c.0.001d.0.00224.The closer the sample mean is to the population mean,a.the larger the sampling errorb.the smaller the sampling errorc.the sampling error equals 1d.None of these alternatives is correct.25.Since the sample size is always smaller than the size of the population, the sample meana.must always be smaller than the population meanb.must be larger than the population meanc.must be equal to the population meand.can be smaller, larger, or equal to the population mean26.As the sample size increases, thea.standard deviation of the population decreasesb.population mean increasesc.standard error of the mean decreasesd.standard error of the mean increases27. A simple random sample from an infinite population is a sample selected such thata.each element is selected independently and from the same populationb.each element has a 0.5 probability of being selectedc.each element has a probability of at least 0.5 of being selectedd.the probability of being selected changes28.In point estimationa.data from the population is used to estimate the population parameterb.data from the sample is used to estimate the population parameterc.data from the sample is used to estimate the sample statisticd.the mean of the population equals the mean of the sample29.The sample mean is the point estimator ofa.pib.Gc.xd.-P30.The expected value of the random variable x isa.the standard errorb.the sample sizec.the size of the populationd.None of these alternatives is correct.31.The standard deviation of all possible x values is called thea.standard error of proportionb.standard error of the meanc.mean deviationd.central variation32.Whenever the population has a normal probability distribution, the sampling distribution of x is a normal probability distribution fora.only large sample sizesb.only small sample sizesc.any sample sized.only samples of size thirty or greater33.The sampling error is thea.same as the standard error of the meanb.difference between the value of the sample mean and the value of the population meanc.error caused by selecting a bad sampled.standard deviation multiplied by the sample size34.Which of the following is(are) point estimator(s)?a. ab.p,c.sd.a35. A population characteristic, such as a population mean, is calleda. a statisticb. a parameterc. a sampled.the mean deviation36. A single numerical value used as an estimate of a population parameter is known asa. a parameterb. a population parameterc. a mean estimatord. a point estimate37.The purpose of statistical inference is to provide information about thea.sample based upon information contained in the populationb.population based upon information contained in the samplec.population based upon information contained in the populationd.mean of the sample based upon the mean of the population38.The number of random samples (without replacement) of size 3 that can be drawn from a population of size 5 isa.15b.10c.20d.12539.For a population with any distribution, the form of the sampling distribution of the sample mean isa.sometimes normal for all sample sizesb.sometimes normal for large sample sizesc.always normal for all sample sizesd.always normal for large sample sizes40. A simple random sample of 28 observations was taken from a large population. The sample mean equaled 50. Fifty is aa.population parameterb.biased estimate of the population meanc.sample parameterd.point estimate41.When s is used to estimate G, the margin of error is computed by usinga.normal distributionb.t distributionc.the mean of the sampled.the mean of the population42.From a population with a variance of 900, a sample of 225 items is selected. At 95% confidence, the margin of error isa.15b. 2c. 3.92d. 443.In order to determine an interval for the mean of a population with unknown standard deviation a sample of 61 items is selected. The mean of the sample is determined to be 23. The number of degrees of freedom for reading the t value isa.22b.23c.60d.6144.If we want to provide a 95% confidence interval for the mean of a population, the confidence coefficient isa.0.485b. 1.96c.0.95d. 1.64545.As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distributiona.becomes largerb.becomes smallerc.stays the samed.None of these alternatives is correct.46.For the interval estimation of p, when o is known and the sample is large, the proper distribution to use isa.the normal distributionb.the t distribution with n degrees of freedomc.the t distribution with n + 1 degrees of freedomd.the t distribution with n + 2 degrees of freedom47.An estimate of a population parameter that provides an interval of values believed to contain the value of the parameter is known as thea.confidence levelb.interval estimatec.parameter valued.population estimate48.The value added and subtracted from a point estimate in order to develop an interval estimate of the population parameter is known as thea.confidence levelb.margin of errorc.parameter estimated.interval estimate49.If an interval estimate is said to be constructed at the 90% confidence level, the confidence coefficient would bea.0.1b.0.95c.0.9d.0.0550.Whenever the population standard deviation is unknown and the population has a normal or near-normal distribution, which distribution is used in developing an interval estimation?a.standard distributionb.z distributionc.alpha distributiond.t distribution51.In interval estimation, the t distribution is applicable only whena.the population has a mean of less than 30b.the sample standard deviation is used to estimate the population standard deviationc.the variance of the population is knownd.the standard deviation of the population is known52.In developing an interval estimate, if the population standard deviation is unknowna.it is impossible to develop an interval estimateb.the standard deviation is arrived at using the rangec.the sample standard deviation can be usedd.it is assumed that the population standard deviation is 153.In order to use the normal distribution for interval estimation of)i when cr is known and the sample is very small, the populationa.must be very largeb.must have a normal distributionc.can have any distributiond.must have a mean of at least 154.From a population that is not normally distributed and whose standard deviation is not known, a sample of 6 items is selected to develop an interval estimate for the mean of the population (y).a.The normal distribution can be used.b.The t distribution with 5 degrees of freedom must be used.c.The t distribution with 6 degrees of freedom must be used.d.The sample size must be increased.55.From a population that is normally distributed, a sample of 25 elements is selected and the standard deviation of the sample is computed. For the interval estimation of pi, the proper distribution to use is thea.normal distributionb.t distribution with 25 degrees of freedomc.t distribution with 26 degrees of freedomd.t distribution with 24 degrees of freedom56.As the sample size increases, the margin of errora.increasesb.decreasesc.stays the samed.increases or decreases depending on the size of the mean57. A 95% confidence interval for a population mean is determined to be 100 to 120. If the confidence coefficient is reduced to 0.90, the interval for(ia.becomes narrowerb.becomes widerc.does not changed.becomes 0.158.The ability of an interval estimate to contain the value of the population parameter is described by thea.confidence levelb.degrees of freedomc.precise value of the population mean p,d.degrees of freedom minus 159.An interval estimate is a range of values used to estimatea.the shape of the population's distributionb.the sampling distributionc. a sample statisticd. a population parameter60.In determining the sample size necessary to estimate a population proportion, which of the following information is not needed?a.the maximum margin of error that can be toleratedb.the confidence level requiredc. a preliminary estimate of the true population proportion Pd.the mean of the population61.What type of error occurs if you fail to reject H o when, in fact, it is not true?a.Type IIb.Type Ic.either Type I or Type II, depending on the level of significanced.either Type I or Type II, depending on whether the test is one tail or two tail62.An assumption made about the value of a population parameter is called aa.hypothesisb.conclusionc.confidenced.significance63.The probability of committing a Type I error when the null hypothesis is true isa.the confidence levelb.卩c.greater than 1d.the Level of Significance64.The p-value is a probability that measures the support (or lack of support) for thea.null hypothesisb.alternative hypothesisc.either the null or the alternative hypothesisd.sample statistic65.The p-valuea.is the same as the Z statisticb.measures the number of standard deviations from the meanc.is a distanced.is a probability66.In hypothesis testing if the null hypothesis is rejected,a.no conclusions can be drawn from the testb.the alternative hypothesis is truec.the data must have been accumulated incorrectlyd.the sample size has been too small67.The level of significance is thea.maximum allowable probability of Type II errorb.maximum allowable probability of Type I errorc.same as the confidence coefficientd.same as the p-value68. A Type II error is committed whena. a true alternative hypothesis is mistakenly rejectedb. a true null hypothesis is mistakenly rejectedc.the sample size has been too smalld.not enough information has been available69.The level of significancea.can be any positive valueb.can be any valuec.is (1 - confidence level)d.can be any value between -1.96 to 1.9670.When the following hypotheses are being tested at a level of significance of aH o: pi > 500H a: ]i < 500the null hypothesis will be rejected if the p-value isa.< aH a : ]i > 10.0%H a : |i > 10.0%H a : ]i < 10.0%d. Ho : pi > 10.0% H a : ]i < 10.0%a. Ho : pi < 85 H a : pi > 85b. Ho : pi < 85 H a : p, >c. Ho : pi > 85 H a : p, < 85d. Ho : pi > 85 H a : pi < 85 a. Ho :pi < 12 H a : pi < 12b. Ho : pi < 12 H a : p, >c. Ho: pi H 12H a : p, = 12b. > ac. > a/2d. < 1 - a/271. When the p-value is used for hypothesis testing, the null hypothesis is rejected if a. p-value < ab. a < p-valuec. p-value > ad. p-value = 1 - a72. In order to test the following hypotheses at an a level of significanceH o : pi < 800H a : ]i > 800the null hypothesis will be rejected if the test statistic Z isa. 巴 Z Qb. <Z ac. < -Z ad. = a73. Your investment executive claims that the average yearly rate of return on the stocks she recommends is more than 10.0%. You plan on taking a sample to test her claim. The correct setof hypotheses is a. H o : pi < 10.0% b. Ho : pi < 10.0%c. Ho : pi > 10.0%74. A weatherman stated that the average temperature during July in Chattanooga is less than 80 degrees. A sample of 32 Julys is taken. The correct set of hypotheses is a . H o : pi > 80 H a : p, <80 b . H o : pi < 80 H a : p, >80 c . H o : —80 H a : p, =80 d . H o : pi < 80 H a : p, >80 75. A student believes that the average grade on the final examination in statistics is at least85. She plans on taking a sample to test her belief. The correct set of hypotheses is76. A soft drink filling machine, when in perfect adjustment, fills the bottles with 12 ouncesof soft drink. Any over filling or under filling results in the shutdown and readjustment of the machine. To determine whether or not the machine is properly adjusted, the correct set ofhypotheses is d. Ho : p = 1277. A two-tailed test is performed at 95% confidence. The p-value is determined to be 0.09. The null hypothesisa.must be rejectedb.should not be rejectedc . could be rejected, depending on the sample sized . has been designed incorrectly7 8Exhibit 2n = 49 x = 54.8 s = 28 H o: pi < 50H a: p, > 50Refer to Exhibit 2. The test statistic isa . 0.1714b . 0.3849c . -1.2d . 1.27 9Refer to Exhibit 2. The p-value is betweena . 0.01 to 0.025b . 0.025 to 0.05c . .05 to 0.1d . 0.1 to 0.28 0Refer to Exhibit 2. If the test is done at the 5% level of significance, the null hypothesisshoulda . not be rejectedb . be rejectedc . Not enough information given to answer this question.d . None of these alternatives is correct.8 1If we are interested in testing whether themeanof population 1 is significantly largerthanthe mean of population 2, thea . null hypothesis should state 内-应 > 0b . null hypothesis should state 内-应巴0c . alternative hypothesis should state p,i - |i2 > 0d . alternative hypothesis should state pii -112 < 08 2If we are interested in testing whether themeanof population 1 is significantlydifferentfrom the mean of population 2, thea . null hypothesis should state 山-应=0b . null hypothesis should state 山-应巴0c . alternative hypothesis should state p,i - |i2 > 0d . alternative hypothesis should state pii -112 < 08 3When developing an interval estimate for the difference between two sample means, withsample sizes of m and n2,a . Ni must be equal to n2b . Ni must be smaller than n2c . Ni must be larger than n2d . Ni and n2 can be of different sizes,84.Independent simple random samples are taken to test the difference between the means of two populations whose variances are not known, but are assumed to be equal. The samplesizes are m = 32 and n2 = 40. The correct distribution to use is thea.t distribution with 73 degrees of freedomb.t distribution with 72 degrees of freedomc.t distribution with 71 degrees of freedomd.t distribution with 70 degrees of freedom85.If two independent large samples are taken from two populations, the sampling distribution of the difference between the two sample meansa.can be approximated by a Poisson distributionb.will have a variance of onec.can be approximated by a normal distributiond.will have a mean of one86.The standard error of x -x2 is thea.--variance of x 严Qb.--variance of the sampling distribution of 区厂乂?c.- ~standard deviation of the sampling distribution of x 严?d.difference between the two means87.In the analysis of variance procedure (ANOVA), ''factor'' refers toa.the dependent variableb.the independent variablec.different levels of a treatmentd.the critical value of F88.The ANOVA procedure is a statistical approach for determining whether or nota.the means of two samples are equalb.the means of two or more samples are equalc.the means of more than two samples are equald.the means of two or more populations are equal89.An experimental design where the experimental units are randomly assigned to the treatments is known asa.factor block designb.random factor designpletely randomized designd.None of these alternatives is correct.90.In an analysis of variance problem involving 3 treatments and 10 observations per treatment, SSE = 399.6. The MSE for this situation isa.133.2b.199.8c.14.8d.30.04 4 4 191.The F ratio in a completely randomized ANOVA is the ratio ofa.MSTR/MSEb.MST/MSEc.MSE/MSTRd.MSE/MST92.The critical F value with 6 numerator and 60 denominator degrees of freedom at a = .05 isa. 3.74b. 2.25c. 2.37d. 1.9693.An ANOVA procedure is applied to data obtained from 6 samples where each sample contains 20 observations. The degrees of freedom for the critical value of F area. 6 numerator and 20 denominator degrees of freedomb. 5 numerator and 20 denominator degrees of freedomc. 5 numerator and 114 denominator degrees of freedomd. 6 numerator and 20 denominator degrees of freedom94.In an analysis of variance problem if SST = 120 and SSTR = 80, then SSE isa.200b.40c.80d.12095.An ANOVA procedure is used for data that was obtained from four sample groups each comprised of five observations. The degrees of freedom for the critical value of F area. 3 and 20b. 3 and 16c. 4 and 17d. 3 and 1996.In ANOVA, which of the following is not affected by whether or not the population means are equal?a.xb.between-samples estimate of c>2c.within-samples estimate of c>2d.None of these alternatives is correct.97. A term that means the same as the term "variable" in an ANOVA procedure isa.factorb.treatmentc.replicationd.variance withinExhibit 3Salary information regarding male and female employees of a large company is shown below.Male FemaleSample Size 64 36Sample Mean Salary (in $1,000)Population Variance (cr2) 128 7298.Refer to Exhibit 3. The point estimate of the difference between the means of the two populations isa.-28b. 3c. 4d.-499.Refer to Exhibit 3. The standard error for the difference between the two means isa. 4b.7.46c. 4.24d. 2.0100.Refer to Exhibit 3. At 95% confidence, the margin of error isa. 1.96b. 1.645c. 3.920d. 2.000101.The coefficient of determinationa.cannot be negativeb.is the square root of the coefficient of correlationc.is the same as the coefficient of correlationd.can be negative or positive102.If the coefficient of determination is a positive value, then the coefficient of correlationa.must also be positiveb.must be zeroc.can be either negative or positived.must be larger than 1103.The mathematical equation relating the independent variable to the expected value of the dependent variable; that is, E(y) = P0 + 卩lx, is known asa.regression equationb.correlation equationc.estimated regression equationd.regression model104.The model developed from sample data that has the form of y = + ijX is known asa.regression equationb.correlation equationc.estimated regression equationd.regression model105.The interval estimate of the mean value of y for a given value of x isa.prediction interval estimateb.confidence interval estimatec.average regressiond.x versus y correlation interval106.The interval estimate of an individual value of y for a given value of x isa.prediction interval estimateb.confidence interval estimatec.average regressiond.x versus y correlation interval107.In a regression analysis the standard error is determined to be 4. In this situation the MSEa.is 2b.is 16c.depends on the sample sized.depends on the degrees of freedom108.In regression analysis, which of the following is not a required assumption about the error term £?a.The expected value of the error term is one.b.The variance of the error term is the same for all values of X.c.The values of the error term are independent.d.The error term is normally distributed.109.In a regression analysis, the coefficient of determination is 0.4225. The coefficient of correlation in this situation isa.0.65b.0.1785c.any positive valued.any value110.In a regression analysis, the coefficient of correlation is 0.16. The coefficient of determination in this situation isa.0.4000b.0.0256c. 4d. 2.56111.In a regression and correlation analysis if r2 = 1, thena.SSE must also be equal to oneb.SSE must be equal to zeroc.SSE can be any positive valued.SSE must be negative112.In a regression and correlation analysis if r2 = 1, thena.SSE = SSTb.SSE= 1c.SSR = SSEd.SSR = SST113.If the coefficient of correlation is a positive value, then the regression equationa.must have a positive slopeb.must have a negative slopec.could have either a positive or a negative sloped.must have a positive y intercept114.If the coefficient of correlation is 0.& the percentage of variation in the dependent variable explained by the variation in the independent variable isa.0.80%b.80%c.0.64%d.64%115.In regression and correlation analysis, if SSE and SST are known, then with this information thea.coefficient of determination can be computedb.slope of the line can be computedc.Y intercept can be computedd.x intercept can be computed116.In regression analysis, if the independent variable is measured in pounds, the dependent variablea.must also be in poundsb.must be in some unit of weightc.cannot be in poundsd.can be any units117.If the coefficient of correlation is -0.4, then the slope of the regression linea.must also be -0.4b.can be either negative or positivec.must be negatived.must be 0.16118.If the coefficient of correlation is a negative value, then the coefficient of determinationa.must also be negativeb.must be zeroc.can be either negative or positived.must be positive119.If a data set has SSR = 400 and SSE = 100, then the coefficient of determination isa.0.10b.0.25c.0.40d.0.80pared to the confidence interval estimate for a particular value of y (in a linear regression model), the interval estimate for an average value of y will bea.narrowerb.widerc.the samed.None of these alternatives is correct.。
最新商务统计学 期中考试卷教程文件

《商务统计》期中考试试题Part I: 单选题(每题2分,共60分)1.The universe or "totality of items or things" under consideration is calleda) a sample.b) a population.c) a parameter.d) a statistic.2.Which of the following is most likely a population as opposed to a sample?a)respondents to a newspaper survey.b)the first 5 students completing an assignment.c)every third person to arrive at the bank.d)registered voters in a county.3. A study is under way in Yosemite National Forest to determine the adult height of Americanpine trees. Specifically, the study is attempting to determine what factors aid a tree inreaching heights greater than 60 feet tall. It is estimated that the forest contains 25,000 adult American pines. The study involves collecting heights from 250 randomly selected adultAmerican pine trees and analyzing the results. Identify the variable of interest in the study.a)The age of an American pine tree in Yosemite National Forest.b)The height of an American pine tree in Yosemite National Forest.c)The number of American pine trees in Yosemite National Forest.d)The species of trees in Yosemite National Forest.4.The British Airways Internet site provides a questionnaire instrument that can be answeredelectronically. Which of the 4 methods of data collection is involved when people complete the questionnaire?a)Published sourcesb)Experimentationc)Surveyingd)Observation5.To monitor campus security, the campus police office is taking a survey of the number ofstudents in a parking lot each 30 minutes of a 24-hour period with the goal of determiningwhen patrols of the lot would serve the most students. If X is the number of students in the lot each period of time, then X is an example ofa) a categorical random variable.b) a discrete random variable.c) a continuous random variable.d) a statistic.6.An insurance company evaluates many numerical variables about a person before decidingon an appropriate rate for automobile insurance. A representative from a local insurance agency selected a random sample of insured drivers and recorded, X, the number of claims each made in the last 3 years, with the following results.X frequency1 142 183124 55 1Referring to the table, how many total claims are represented in the sample?a)15b)50c)111d)250(For Q7 and Q8) A survey was conducted to determine how people rated the quality of programming available on television. Respondents were asked to rate the overall quality from 0 (no quality at all) to 100 (extremely good quality). The stem-and-leaf display of the data is shown below.Stem Leaves3 244 034789995 01123456 125667 0189 27.Referring to the table, what percentage of the respondents rated overall television qualitywith a rating of 80 or above?a)0b) 4c)96d)1008.Referring to the table, what percentage of the respondents rated overall television qualitywith a rating between 50 and 75?a)11b)40c)44d)56(For Q9 and Q10) The following are the durations in minutes of a sample of long-distance phone calls made reported by one long-distance carrier.Time (in Minutes) Relative Frequency0 but less than 5 0.375 but less than 10 0.2210 but less than 15 0.1515 but less than 20 0.1020 but less than 25 0.0725 but less than 30 0.0730more 0.029.Referring to the table, if 1,000 calls were randomly sampled, how many calls lasted under10 minutes?a)220b)370c)410d)59010.Referring to the table, if 100 calls were randomly sampled, how many calls lasted 15minutes or longer?a)10b)14c)26d)7411.You have collected data on the approximate retail price (in $) and the energy cost per year(in $) of 15 refrigerators. Which of the following is the best for presenting the data?a) A pie chart.b) A scatter diagram.c) A Pareto diagram.d) A contingency table.(For Q12 and Q13) The histogram below represents scores achieved by 200 job applicants on a personality profile.12.Referring to the histogram, ________ percent of the job applicants scored between 10 and20.a)10%b)20%c)30%d)40%13.Referring to the histogram, the number of job applicants who scored between 30 and below60 is _______.a)20b)40c)60d)8014.Which measure of central tendency can be used for both numerical and categoricalvariables?a)Arithmetic mean.b)Median.c)Mode.d)Standard deviation.15.Which of the following statements about the median is not true?a)It is more affected by extreme values than the arithmetic 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 "normal" distributions.16.When extreme values are present in a set of data, which of the following descriptivesummary measures are most appropriate:a)CV and range.b)arithmetic mean and standard deviation.c)interquartile range and median.d)variance and interquartile range.17.A probability distribution is an equation thata)associates a particular probability of occurrence with each outcome in the samplespace.b)measures outcomes and assigns values of X to the simple events.c)assigns a value to the variability in the sample space.d)assigns a value to the center of the sample space.18.In a binomial distributiona)the random variable Xb)the probability of event of interest is stable from trial to trial.c)the number of trials nd)the results of one trial are dependent on the results of the other trials.19.A lab orders 100 rats a week for each of the 52 weeks in the year for experiments that thelab conducts. Prices for 100 rats follow the following distribution:Price: $10.00 $12.50 $15.00Probability: 0.35 0.40 0.25How much should the lab budget for next year’s rat orders be, assuming this distribution does not change?a)$520b)$637c)$650d)$78020.A multiple-choice test has 30 questions. There are 4 choices for each question. A studentwho has not studied for the test decides to answer all questions randomly. What type of probability distribution can be used to figure out his chance of getting at least 20 questions right?a)binomial distribution.b)Poisson distribution.c)normal distribution.d)none of the above.21.In its standardized form, the normal distributiona)has a mean of 0 and a standard deviation of 1.b)has a mean of 1 and a variance of 0.c)has an area equal to 0.5.d)cannot be used to approximate discrete probability distributions.22.For some positive value of Z, the probability that a standard normal variable is between 0and Z is 0.3340. The value of Z isa)0.07b)0.37c)0.97d) 1.0623.The owner of a fish market determined that the average weight for a catfish is 3.2 poundswith a standard deviation of 0.8 pound. A citation catfish should be one of the top 2% in weight. Assuming the weights of catfish are normally distributed, at what weight (in pounds) should the citation designation be established?a) 1.56 poundsb) 4.44 poundsc) 4.84 poundsd) 5.20 pounds24.If a particular batch of data is approximately normally distributed, we would find thatapproximatelya) 2 of every 3 observations would fall betweenb) 4 of every 5 observations would fall betweenc)d)All the above.25.Which of the following about the binomial distribution is not a true statement?a)The probability of event of interest must be constant from trial to trial.b)Each outcome is independent of the other.c)The random variable of interest is continuous.d)Each outcome may be classified as either "event of interest" or "not event ofinterest."26.Why is the Central Limit Theorem so important to the study of sampling distributions?a)It allows us to disregard the size of the sample selected when the population is notnormal.b)It allows us to disregard the shape of the sampling distribution when the size of thepopulation is large.c)It allows us to disregard the size of the population we are sampling from.d)It allows us to disregard the shape of the population when n is large.27.Suppose a sample of n = 50 items is drawn from a population of manufactured products andthe weight, X, of each item is recorded. Prior experience has shown that the weight has aprobability distribution with = 6 ounces and = 2.5 ounces. Which of the following isa)The mean of the sampling distribution is 6 ounces.b)The standard deviation of the sampling distribution is 2.5 ounces.c)The shape of the sample distribution is approximately normal.d)All of the above are correct.28.For some positive value of X, the probability that a standard normal variable is between 0and +2X is 0.1255. The value of X isa)0.99b)0.40c)0.32d)0.1629.A campus program evenly enrolls undergraduate and graduate students. If a random sampleof 4 students is selected from the program to be interviewed about the introduction of a new fast food outlet on the ground floor of the campus building, what is the probability that all 4 students selected are undergraduate students?a)0.0256b)0.0625c)0.16d) 1.0030.If two events are collectively exhaustive, what is the probability that both occur at the sametime?a)0.b)0.50.c) 1.00.d)Cannot be determined from the information given.Part II: 计算题:Q1. 某证券公司为了分析上市公司股票价格与公司净资产收益率的关系,收集了各个上市公(10分)。
《商务统计学》题集

《商务统计学》题集一、选择题(每题2分,共10分)1.下列哪项不属于商务统计学的应用范围?A. 市场调查B. 质量控制C. 财务分析D. 天气预测2.在统计学中,总体是指什么?A. 研究的全部对象B. 研究中的一部分对象C. 某个具体的样本D. 某一特定数据3.下列哪种抽样方法是随机抽样?A. 方便抽样B. 系统抽样C. 配额抽样D. 判断抽样4.如果一组数据的均值是20,中位数是22,那么这组数据的分布可能是?A. 正偏态B. 负偏态C. 对称分布D. 无法确定5.在回归分析中,解释变量和被解释变量分别是什么?A. 因变量和自变量B. 自变量和因变量C. 都是自变量D. 都是因变量二、填空题(每空1分,共10分)1.在统计学中,用来衡量数据分布集中趋势的指标有______、______和______。
2.若一组数据的四分位数Q1=10,Q2=20,Q3=30,则该组数据的中位数为______。
3.在假设检验中,如果P值小于显著性水平α,则我们______原假设。
4.统计表中,频数和频率分别表示数据的______和______。
5.在回归分析中,回归系数的经济意义是解释变量每增加一个单位,被解释变量平均增加______单位。
三、判断题(每题1分,共10分)1.统计学的目的是收集、整理、分析和解释数据,从而帮助人们做出决策。
( )2.在正态分布中,均值、中位数和众数三者相等。
( )3.标准差是衡量数据波动大小的一个重要指标,标准差越大,说明数据的波动越大。
( )4.在假设检验中,如果P值大于显著性水平α,则我们有足够的证据拒绝原假设。
( )5.相关系数r的取值范围是[-1, 1],r=1表示完全正相关,r=-1表示完全负相关。
( )6.如果一组数据的偏度系数大于0,则说明这组数据是正偏态分布。
( )7.在抽样调查中,样本容量越大,抽样误差就越小。
( )8.统计推断是通过样本数据来推断总体的特征。
( )9.移动平均法是一种常用的时间序列预测方法。
商务经济统计试题及答案

商务经济统计试题及答案一、单项选择题1. 商务统计中,用于描述数据集中趋势的指标是:A. 方差B. 标准差C. 平均数D. 众数答案:C2. 在商务经济统计中,下列哪项不是统计量?A. 均值B. 标准差C. 样本容量D. 极差答案:C3. 以下哪项不是时间序列分析的类型?A. 季节性分析B. 趋势分析C. 相关性分析D. 循环分析答案:C二、多项选择题1. 商务统计中,以下哪些因素会影响数据的变异性?A. 数据的分布形态B. 数据的集中趋势C. 数据的离散程度D. 数据的样本大小答案:A、C2. 在进行商务经济预测时,常用的统计方法包括:A. 回归分析B. 指数平滑法C. 移动平均法D. 季节性调整答案:A、B、C三、简答题1. 简述商务统计中的指数平滑法的基本原理。
答案:指数平滑法是一种时间序列预测方法,它通过对历史数据加权平均来预测未来值。
权重随着时间的递减而递减,即近期的数据比远期的数据在预测中占有更大的权重。
这种方法可以平滑掉数据中的随机波动,从而更好地反映数据的趋势。
2. 描述商务统计中相关系数的计算方法及其意义。
答案:相关系数是用来衡量两个变量之间线性关系强度和方向的统计量。
其计算公式为:\[ r = \frac{\sum (X_i - \bar{X})(Y_i -\bar{Y})}{\sqrt{\sum (X_i - \bar{X})^2 \sum (Y_i -\bar{Y})^2}} \] 其中,\( X_i \) 和 \( Y_i \) 分别是两个变量的观测值,\( \bar{X} \) 和 \( \bar{Y} \) 是它们的平均值。
相关系数的值介于-1和1之间,值越接近1或-1表示变量间的线性关系越强,正值表示正相关,负值表示负相关。
四、计算题1. 假设有一组商务数据,其平均值为100,标准差为15。
如果某次测量结果为120,计算该结果的Z分数。
答案:Z分数的计算公式为:\[ Z = \frac{(X - \mu)}{\sigma} \]其中,\( X \) 是测量结果,\( \mu \) 是平均值,\( \sigma \) 是标准差。
商务统计试题及答案

商务统计试题及答案### 商务统计试题及答案#### 一、选择题1. 统计数据收集的方法不包括以下哪项?- A. 观察法- B. 实验法- C. 调查法- D. 假设法答案:D2. 以下哪项不是描述性统计分析的内容?- A. 数据的分类- B. 数据的汇总- C. 数据的推断- D. 数据的图表展示答案:C3. 在统计学中,中位数是指:- A. 数据集中出现次数最多的数值- B. 数据集的算术平均值- C. 将数据集从小到大排列后位于中间位置的数值 - D. 所有数据的和除以数据的个数答案:C#### 二、简答题1. 解释什么是标准差,并简述其在商务统计中的重要性。
标准差是衡量一组数据离散程度的统计量,它表示数据集中的数值与平均值的偏差平方的平均数的平方根。
在商务统计中,标准差用于评估数据的波动性,帮助决策者了解业务风险和市场波动。
2. 描述相关系数的概念及其在商务分析中的应用。
相关系数是度量两个变量之间线性关系强度和方向的统计指标。
在商务分析中,相关系数可以用来评估不同因素对业务结果的影响,例如,销售额与广告支出之间的关系。
#### 三、计算题1. 给定以下数据集:10, 12, 15, 20, 25, 请计算平均值、中位数和标准差。
- 平均值 = (10 + 12 + 15 + 20 + 25) / 5 = 18- 中位数 = 15(数据集从小到大排列后位于中间位置的数值)- 标准差= √[(Σ(xi - 平均值)²) / n] = √[(10 - 18)² + (12 - 18)² + ... + (25 - 18)²] / 5 ≈ 5.392. 假设某公司连续5个月的销售额分别为:30万、35万、40万、45万和50万。
计算这5个月的平均销售额和销售额的增长趋势。
- 平均销售额 = (30 + 35 + 40 + 45 + 50) / 5 = 40万- 销售额的增长趋势可以通过计算每月销售额的增长率来分析,例如,从第一个月到第二个月的增长率为 (35 - 30) / 30 * 100% = 16.67%。
商务统计复习题集.doc

商务统计复习题集《商务统计习题》一CZW1一、单选题;1、在数据采集活动中,进行观测记录的基本单位与总体屮的个体()。
A、必须相同B、必须不同C、可以相同,也可以不同D、完全没有关系2、对于内部差异很大口有明显的不同类型界限或标志的总体,进行抽样调查应该采用的抽样方式是()。
A、简单随机抽样B、系统抽样C、分层抽样D、整群抽样3、构成次数分布表的基本要素是()oA、各个个体的名称与指标数值B、各组变量值与次数C、各组变量值与其方差D、各组均值与方差4、如果观测变量的取值很多且数值成比例变化,则编制次数分布表时采用()。
A、单值B、等距分组C、异距分组D、复合分组5、统计指标是用来测度统计活动研究对象某种特征数量的()。
《商务统计习题》一czw2A、概念B、数值C、概念和数值D、数值尺度6、统计指标口径是指统计指标所包括的()。
A、总体大小B、个体多少C、理论范围D、具体范围7、统计推断是一种()。
A、演绎推理B、完全归纳推理C、不完全归纳推理D、非逻辑推理。
8、根据斯特吉斯公式,对于样本容量为1000的一个观测样本,采用等距分组,英组数应该为()。
A、9 组B、10 组C、11 组D、12 组9、从0-1分布总体屮进行不放回抽样,样本屮具有1值的个体数服从()。
A、两点分布B、二项分布C、超几何分布D、泊松分布10、对于由观测变量的各个分组和各组变量总值顺序排列的分组分布表,计算算术平均数需采用的计算公式为()0A、简单算术平均数B、加权算术平均数C、简单调和平均数D、加权调和平均数口、随机变量的观测值中出现次数最多的变量值是该变量的()oA、众数B、中位数C、极值D、均值12、两个观测值之间如果存在同方向的线性函数关系,则二者的相关关系为()。
A、0B、1C、-1D、0.5)o15、变量x 和y 的相关系数的符号,取决于()。
A 、正态分布B 、x 分布C 、t 分布D 、均匀分布2 18、抽样分布是指( )oA 、抽取样本的总体分布B 、样本自身的分布C 、样本统计量的分布D 、抽样观测变量的分布 估计量是一个( )。
商务统计学试题

商务统计学[单项选择题]1、在数据采集活动中,进行观测记录的单位与总体中的个体()A.必须相同B.必须不同C.可以相同,也可以不同D.完全没有关系参考答案:C[单项选择题]2、对于内部差异很大且有明显的不同类型界限或标志的总体,进行抽样调查应该采用的抽样方式是()A.简单随机抽样B.系统抽样C.分层抽样D.整群抽样参考答案:C[单项选择题]3、如果观测变量的取值很多且数值成比例变化,则编制次数分布表时采用()A.单值B.等距分组C.异距分组D.复合分组参考答案:C[单项选择题]4、统计指标是用来测度统计活动研究对象某种特征数量的()A.概念B.数值C.概念和数值D.数值尺度参考答案:A[单项选择题]5、统计推断是一种()A.演绎推理B.完全归纳推理C.不完全归纳推理D.非逻辑推理参考答案:C[单项选择题]6、根据斯特吉斯公式,对于样本容量为1000的一个观测样本,采用等距分组,其组数应该为()A.9组B.10组C.11组D.12组参考答案:C[单项选择题]7、对于由观测变量的各个分组和各组变量总值顺序排列的分组分布表,计算算术平均数需采用的计算公式为()A.简单算术平均数B.加权算术平均数C.简单调和平均数D.加权调和平均数参考答案:D[单项选择题]8、随机变量的观测值中出现次数最多的变量值是该变量的()A.众数B.中位数C.极值D.均值参考答案:A[单项选择题]9、两个观测值之间如果存在同方向的线性函数关系,则二者的相关关系为()A.0B.1C.-1D.0.5参考答案:B[单项选择题]10、对于同一数据,所计算出的平均差与标准差相比,通常有()A.平均差大于标准差B.平均差小于标准差C.平均差等于标准差D.二者关系不定参考答案:B[单项选择题]11、变量x和y的相关系数的符号,取决于()A.变量x的标准差B.变量y的标准差C.变量x和y两个标准差的乘积D.变量x和y的协方差参考答案:D[单项选择题]12、对于从所考察总体中随机抽取的一个大样本,其样本均值近似服从()A.正态分布B.x2分布C.t分布D.均匀分布参考答案:A[单项选择题]13、抽样分布是指()A.抽取样本的总体分布B.样本自身的分布C.样本统计量的分布D.抽样观测变量的分布参考答案:C[单项选择题]14、如果θ^是该参数θ的一致估计,则随着样本容量n的增大,有()A.θ^的数值接近于总体参数θB.θ^的期望等于总体参数θC.θ^的方差接近于总体参数θD.θ^的方差接近于总体方差σ2参考答案:A[单项选择题]15、在假设检验中,犯第一类错误的概率等于()A.αB.βC.1-αD.1-β参考答案:A[单项选择题]16、在给定的显著性水平之下,进行假设检验,确定拒绝域的依据是()A.原假设为真的条件下检验统计量的概率分布B.备择假设为真的条件下检验统计量的概率分布C.观测变量的总体概率分布D.观测变量的样本分布参考答案:A[单项选择题]17、在单因子方差分析中,如果各个因子水平效应相同的原假设为真,则组间平方和SSA()A.等于0B.等于总平方和C.完全由观测的随机误差引起D.完全由各因子水平的差异引起参考答案:C[单项选择题]18、在方差分析中,所考察的影响观测变量的各个因子都必须()A.属性化B.数量化C.同质化D.差异化参考答案:A[单项选择题]19、使用最小二乘法估计得出的样本回归直线必然通过点()A.(0,0)B.(x,0)C.(0,y)D.(x,y)参考答案:D[单项选择题]20、居民家庭人均消费支出的差异随着家庭人均收入的提高而增加,这种现象称为()A.直线趋势B.曲线趋势C.异方差D.异常数据参考答案:C[单项选择题]21、累计采样所得到的时间序列是()A.时点序列B.时期序列C.特征序列D.平稳序列参考答案:B更多内容请访问《睦霖题库》微信公众号[单项选择题]22、已知一个时间序列的最初水平和最末水平,要计算各期的平均增长速度,则应采用的计算方法为()A.算术平均法B.几何平均法C.代数平均法D.调和平均法参考答案:B[单项选择题]23、如果时间序列的环比增长量大致相等,则应采用的趋势模型为()A.直线趋势模型B.指数曲线趋势模型C.二次曲线趋势模型D.修正指数曲线趋势模型参考答案:A[单项选择题]24、非概率型决策是一种()A.确定性决策B.非确定性决策C.等可能性决策D.非计算性决策参考答案:B[单项选择题]25、期望损益准则特别适用于()A.重复性决策B.一次性决策C.确定性决策D.非概率型决策参考答案:A[单项选择题]26、劳动生产率指数是一个()。
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A. 全及总体是唯一确定的B. 样本是唯一确定的
C.总体指标是固定的量D.总体指标是随机变量
E. 样本指标是随机变量
9、时间数列的速度指标具体包括( )
A. 发展速度B. 平均发展速度C. 增长速度
D. 增长量E. 平均增长速度
10、对某地区的电视机的销售量进行分析,适宜采用的模型是( )
7、位置平均数有中位数、众数和次数。( )
8、因素分析法的依据是指标体系。( )
9、抽样极限误差总是大于抽样平均误差。( )
10、抽样调查可以不遵循随机原则。( )
11、在其他条件不变的情况下,判定系数越大,估计标准误差就越大;反之,估计标准误差就越小。( )
12、编制时间数列的基本原则是保证数列中各项观察值具有可比性。( )
年份
国内生产总值y
固定资产投资完成额x
2003
195
20
2004
210
20
2005
244
26
2006
264
35
2007
294
52
2008
314
56
2009
360
81
2010
432
131
2011
481
149
2012
567
163
2013
655
232
2014
704
202
A.两者相等B.前者比后者大
C.前者比后者小D.不能确定大小
13、两变量之间线性相关程度越弱,则相关系数( )
A.趋近于1B.越趋近于0C.越大于1D.越小于1
14、累积增长量与其相应的各个逐期增长量的关系表现为()
A.累积增长量等于相应的各个逐期增长量之积
B.累积增长量等于相应的各个逐期增长量之和
A. 不变B. 无法判断C.缩小1/100D.扩大10倍
8、比较两个单位的数据资料,甲的标准差小于乙的标准差,则( )
A.两个单位的平均数代表性相同
B.甲单位的平均数代表性大于乙单位
C.乙单位的平均数代表性大于甲单位
D.不能确定哪个单位的平均数代表性大
9、根据指数研究的范围不同,可以把他分为( )
A.个体指数和总指数B.平均指数和加权指数
6、是非标志的标准差是( )
A. B. C.
D. E.
7、设p为价格,q为销售量,则总指数 的意义是( )
A. 综合反映多种商品的销售量的变动程度
B. 综合反映商品价格和销售量的变动程度
C. 综合反映商品销售额的变动程度
D. 反映商品销售量变动对销售额变动的影响程度
E. 综合反映多种商品价格的变动程度
2、填报单位是调查项目的承担者,调查单位则是负责向上报告调查内容的单位。( )
3、通常对森林资源量的调查是经常性调查。( )
4、简单分组就是指对研究现象按一个标志进行的分组。 ( )
5、对于离散型变量数列,只能编制单项数列,不能编制组距数列。( )
6、总量指标按其反映的内容不同可分为总体单位总量和总体标志总量,按其反映的时间状况不同可分为时期指标和时点指标。 ( )பைடு நூலகம்
13、如果历年的环比发展速度相同,则其环比增长速度也相同。( )
14、季节变动的发生周期较循环变动的发生周期要长。( )
15、数量性是统计研究对象最基本的特点。( )
二、单项选择题.(1分×15=15分)
1、下列属于品质标志的是( ).
A. 工人年龄B. 工人性别C. 工人体重D. 工人工资
2、统计调查的基本目的就是要取得真实可靠的( )。
A.只能编制组距式数列B.只能编制单项式数列
C. 不能编制组距式数列D.不能编制单项式数列
E. 既能编制单项式数列,又能编制组距式数列
4、下列指标中属于强度相对指标的是( )
A. 人口密度B. 人均国民生产总值C. 人口出生率
D. 人口自然增长率E. 男女性别比例
5、属于位置平均数的种类有( )
A. 算术平均数B. 调和平均数C. 几何平均数D. 众数E. 中位数
C.综合指数和平均指数D.动态指数和静态指数
10、质量指标指数的同度量因素一般是( )
A.基期质量指标B.报告期质量指标
C.基期数量指标D.报告期数量指标
11、某厂连续生产,在一天中每隔2个小时取出一份产品进行检验,这种检验是( )
A.简单随机抽样B.类型抽样C.等距抽样D.整群抽样
12、假定10亿人口的大国和100万人口的小国的居民年龄变异程度相同。现在各自用重复抽样方法抽取本国人口的1%计算平均年龄,则平均年龄的抽样平均误差( )。
A. 第二手资料B. 已分组资料C. 原始资料D. 数列资料
3、一个等距数列末组为开口组,已知其下限为400,相邻组组距为50,则该组的组中值为( )
A. 450B. 425C. 350D. 325
4、某地农业总产值在工农业总产值中的比重由2000年的43%下降到2007年的31%,这两个指标 ()。
商务统计学试卷D
命题方式:统一命题
佛山科学技术学院2014—2015学年第二学期
《商务统计学》课程期末考试试题(D卷闭卷)
专业、班级:姓名:学号:
题号
一
二
三
四
五
总成绩
得 分
一、判断题.(1分×15=15分,正确的打“√”,错误的打“×”)
1、以企业为单位来研究企业规模大小时,统计出企业的职工人数属于总体单位总量。 ( )
C. 该学校某学生的入学成绩D. 该学校在校人数
E. 该学校学生就业率
2、重点调查的特点是( )
A. 重点单位的数目占总体单位总数很少
B. 主要目的是要了解调查对象的基本情况
C. 重点单位的标志值总量占总体标志总量的绝大比重
D. 用来推算总体的指标值
E. 选取有典型代表意义的单位
3、对于连续型变量,一般情况下( )
A. 直线模型B.指数模型C.修正指数曲线
D.龚柏兹曲线E.移动平均法
四、简答题(6分×2=12分)
1、简述统计调查的组织形式。
2、什么是同度量因素确定同度量因素的基本原则是什么
五、综合业务计算题(1小题6分,2、3小题各10分,4小题12分,共38分)
1.资料:某企业各月库存额资料如下:(6分)单位:万元
C.累积增长量等于相应的各个逐期增长量之差
D.以上都不对
15、移动平均的平均项数越大,则它( )
A.对数列的平滑修匀作用越强B.对数列的平滑修匀作用越弱
C.对数列数据的变化反应越快D.对数列数据的变化反应越大
三、多项选择题(2分×10=20分)
1、以某大学的学生为总体,则统计指标有( )
A. 该学校的学生男女生比例B. 该学校学生的平均年龄
3.资料:海粤股份有限公司生产三种商品的销售资料如下:
商品名称
销售额(万元)
销售量07年比06年增长%
2006 年
2007年
甲
150
180
8
乙
200
240
5
丙
400
450
15
(1)试计算销售量指数。
(2)试计算销售额指数和价格指数。
(3)试从相对数和绝对数两方面简要分析销售额变动的影响因素。
4.资料:某省2003—2014年国内生产总值和固定资产投资完成额资料如下表所示。要求:(1)国内生产总值y对固定资产投资完成额x的直线回归方程。(2)若2015年该省国内生产总值为230亿元,预测该省的固定资产投资完成额为多少亿元?
A.都是动态相对数B.都是比较相对数C.都是结构相对数
D.一个是结构相对数,一个是动态相对数
5、下列属于时点指标的是()。
A. 商品销售利润B.商品销售成本C.商品销售量D.商品价格
6、平均指标反映了总体分布的()。
A. 集中趋势B. 离中趋势C. 长期趋势D. 基本趋势
7、假定各标志值对应的权数都缩小1/10,各标志值不变,则算术平均数()
日 期
1月1日
3月1日
5月1日
7月1日
11月1日
12月31日
库存额
125
112
115
106
128
94
试计算该企业上半年和全年的平均库存额。(计算结果保留两位小数)
2.资料:某电子元件厂随机抽选100个元件检验,其中有4个元件为废品,又知抽样数量产品总数的千分之一,若以95.45%的概率保证,试估计该厂生产的电子元件的废品率范围。若极限误差减少一半,其他条件不变,在重复抽样的情况下,需抽多少个元件检验在不重复抽样的情况下又如何