商务统计习题

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商务统计学复习题-统计学练习题一、单项选择题1.下列数据属于名义尺度(nominal scale)的是（）A．性别B) 年龄C)体重D)年级2.下列数据属于名义尺度(nominal scale)数据的是（）。

A．性别 B. 年龄 C. 体重 D. 年级3.下列数据属于区间尺度(order scale)数据的是（）。

A．气温 B. 产量 C. 体重 D.年级4.针对z-分数(z-score)，下列说法不正确的是（）。

A. 若z-分数小于0，则变量值小于平均数B. 若z-分数大于0，则变量值大于平均数C. 若z-分数等于0，则变量值等于平均数D. 若z-分数等于0，则变量值等于05.下列选项中，不属于变异指标(measure of variability)的是（）A) 平均数B) 极差C) 标准差D) 变异系数6.下列几种分布中，属于离散型随机变量(discrete random variable)的分布的是（）。

A. 二项分布B. 泊松分布C. 指数分布D. 超几何分布7.下列几种常见的分布中，属于连续型随机变量(continuous random variable)的分布的是（）。

A. 二项分布B. 泊松分布C. 指数分布D. 超几何分布8.一个特定研究中感兴趣的对象的全体称为（）A) 样本(sample) B) 参数(a parameter)C) 统计量(statistic)D) 总体(population)9. 下列不属于描述统计(descriptive statistics)常用形式的是（）A) 绘制图形B) 绘制表格C) 计算平均数D) 区间估计10. 下列属于统计推断(statistical inference)内容的是（）A) 绘制图形B) 绘制表格C) 计算平均数D) 区间估计11. 下列图形中，不能用于分类数据(categorical data)的是（）A)条形图B) 茎叶图C) 柱状图D) 饼状图12. 商务数据的相对频数( relative frequency)之和为（）A)1 B) 2 C) 0 D)不确定13. 若偏度=-0.85，则该组数据的分布形态为（）A)适度左偏B) 适度右偏C) 对称D) 无法确定14. 若偏度=0.85，则该组数据的分布形态为（）A.适度左偏B.适度右偏C.对称D.无法确定15.当总体服从正态分布时，样本均值x的抽样分布(sampling distribution)服从于（）。

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.。

《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5精选全文

精选全文完整版（可编辑修改）《商务统计》试题5------------------------------------------------------------------------------------------------------------------------一、判断题（每题1分，共10分）1.应用切比雪夫定理估计与平均数的距离在z个标准差之内的数据项所占比例时，z的取值可以是任意正数( )。

2.条形图和直方图都可以用于描述分类数据的频数分布、相对频数分布或百分比频数分布( )。

3.在样本容量一定的情况下，为了确保更高的置信度，置信区间的宽度必须变大( )。

4.事件A与其补A c是互斥的( )。

5.无论是单侧检验还是双侧检验，如果p值≤α，则拒绝原假设H0( )。

6.对于简单随机样本，样本均值x̅的数学期望、标准差受到样本容量n的影响 ( )。

7.在联列表中，两个变量必须都是分类变量或者都是数值型变量( )。

8.当分类数据用数值表示时，可以进行有意义的算术运算( )。

9.在满足一定条件时，可以用正态分布近似计算二项分布 ( )。

10.方差分析仅能用于实验性研究得到的数据而不能用于观测性研究得到的数据( )。

二、单项选择题（每题2分，共30分）1.由于改变生产方法所需的时间和成本都很大，所以在一种新方法实施之前，制造负责人必须使管理人员确信，推荐的制造方法能降低成本。

目前生产方法的平均成本是每小时22美元。

一项调研工作是在样本生产期同，测量新方法的成本。

以下假设合适的是( )。

A. H0:μ≥22 H a:μ<22B.H0:μ≤22 H a:μ>22C.H0:μ>22 H a:μ≤22D.H0:μ<22 H a:μ≥222.以下关于众数的说法错误的是( )。

A.众数是数据集中出现频率最高的数据值B.众数仅适用于数值型数据C.众数是一种位置度量指标D.众数有可能存在两个或更多3.以下关于事件的概率说法错误的是( )。

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（）。

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Practice Test 1 Business Statistics:Multiple Choice: Each is worth two pointsIdentify the letter of the choice that best completes the statement or answers the question. **Skip 15-17,18,20 Ch10-12,13 Material____ 1. The sum of the relative frequencies for all classes will always equal a.the sample sizeb.the number of classesc.oned.any value larger than one____ 2. The interquartile range isa.the 50th percentileb.another name for the variancec . the difference between the largest and smallest valuesd . the difference between the third quartile and the first quartile____ 3. The standard deviation of a sample of 100 observations equals 64. The variance of the sample equalsa.8b.10c.6400d.4,096____ 4. The numerical value of the standard deviation can never bea.larger than the variance.cnegative.smaller than the varianced.____ 5. The set of all possible sample points (experimental outcomes) is called aa sample.an eventb.cthe sample space.a populationd.____ 6. A random variable that can assume only a finite number of values is referred to as a(n)infinite sequencea.bfinite sequence.discrete random variablec.discrete probability functiond.Exhibit 5-11A local bottling company has determined the number of machine breakdowns permonth and their respective probabilities as shown below:Number ofBreakdowns Probability0 0.121 0.382 0.253 0.184 0.07____ 7. Refer to Exhibit 5-11. The probability of at least 3 breakdowns in a month is a0.5b0.10.c0.30.d0.90.____ 8. A normal probability distributionis a continuous probability distributiona.bis a discrete probability distribution.can be either continuous or discretec.dmust have a standard deviation of 1.Exhibit 6-6The starting salaries of individuals with an MBA degree are normally distributedwith a mean of $40,000 and a standard deviation of $5,000.____ 9. Refer to Exhibit 6-6. What percentage of MBA's will have starting salaries of $34,000 to $46,000?a38.49%.38.59%b.50%c.76.98%d.____10. Given that Z is a standard normal random variable, what is the value of Z if the area between -Z and Z is 0.901?1.96a.-1.96b.0.4505c.d 1.65____11. Which of the following is not a measure of central location?amean.medianb.variancec.moded.____12. The descriptive measure of dispersion that is based on the concept of a deviation about the mean isthe rangea.the interquartile rangeb.the absolute value of the rangec.the standard deviationd.____13. Which of the following symbols represents the mean of the population?aσ2.bσ.cμ.d.____14. Which of the following symbols represents the size of the sampleaσ2.bσ.Nc.d n____15. If two events are independent, thenathey must be mutually exclusive.the sum of their probabilities must be equal to oneb.ctheir intersection must be zero.None of these alternatives is correct..d.____16. Which of the following statements is(are) always true?a-1 ≤ P(E i) ≤1.P(A) = 1 - P(A c)b.P(A) + P(B) = 1c.d∑P ≥ 1.____17. A measure of the average value of a random variable is called a(n)variancea.bstandard deviation.expected valuec.coefficient of variationd.____18. Four percent of the customers of a mortgage company default on their payments. A sample of five customers is selected. What is the probability that exactly twocustomers in the sample will default on their payments?0.2592a.0.0142b..0.7408d.____19. The expected value of a discrete random variablea. is the most likely or highest probability value for the randomvariableb. will always be one of the values x can take on, although it maynot be the highest probability value for the random variablec. is the average value for the random variable over many repeats ofthe experimentd. None of these alternatives is correct.____20. Which of the following is not a property of a binomial experiment?a. the experiment consists of a sequence of n identical trialsb. each outcome can be referred to as a success or a failurec. the probabilities of the two outcomes can change from onetrial to the nextd. the trials are independentExhibit 5-9The probability distribution for the daily sales at Michael's Co. is given below.Daily Sales(In $1,000s) Probability40 0.150 0.460 0.370 0.2____21. Refer to Exhibit 5-9. The expected daily sales are$55,000a.$56,000b.$50,000c.$70,000d.azero.-0.5b.c0.5.oned.Exhibit 6-2The weight of football players is normally distributed with a mean of 200 poundsand a standard deviation of 25 pounds.____23. Refer to Exhibit 6-2. What percent of players weigh between 180 and 220 pounds?a. 28.81%b0.5762%.c. 0.281%57.62%d.Exhibit 6-6The starting salaries of individuals with an MBA degree are normally distributedwith a mean of $40,000 and a standard deviation of $5,000.____24. Refer to Exhibit 6-6. What is the probability that a randomly selected individual with an MBA degree will get a starting salary of at least $47,500?a. 0.4332b. 0.9332c. 0.0668d. 0.5000Short Answer/Problems1.The following data represent the daily demand (y in thousands of units) and the unit price (xin dollars) for a product.Daily Demand (y) Unit Price (x)47 139 335 544 334 620 815 16a. Compute and interpret the sample covariance for the above data.b. Compute and interpret the sample correlation coefficient.2.The daily dinner bills in a local restaurant are normally distributed with a mean of $28 and astandard deviation of $6.a. What is the probability that a randomly selected bill will be at least $39.10?b. What percentage of the bills will be less than $16.90?c. What are the minimum and maximum of the middle 95% of the bills?d. If twelve of one day's bills had a value of at least $43.06, how many bills didthe restaurant collect on that day?3.Below you are given a partial computer output based on a sample of 7 observations, relatingan independent variable (x) and a dependent variable (y).Predictor Coefficient StandardErrorConstant 24.112 8.376x -0.252 0.253Analysis of VarianceSOURCE SSRegression 196.893Error 94.822a. Develop the estimated regression line.b. If you are given that x = 50, find the estimate of y based on your regressionequation.c. Determine the coefficient of determination and interpret your answer. Solutions to MC1. C2. D3. D4. C5. C6. C7. D8. A9. D 10. D11. C 12. D 13. C 14. D 15. D 16. B 17. C 18. B19. C 20. C 21. B 22. C 23. D 24. C 25. C 26. A27. B 28. D 29. CSolutions to Short Answer1. ANS:a. -47 (rounded). Since the covariance is negative, it indicates a negativerelationship between x and y.b. -0.922. There is a strong negative relationship between x and y.2. ANS:a. 0.0322b. 0.0322d. 2,0003. ANS:a. = 24.112 + 0.816xb. If x = 50 then = 24.112 + 0.816x 24.1 + 0.82 ( 50 ) = 65.1c. 0.675 So there is a fairly strong positive relationship between x and y.Practice Test 2 Business Statistics:Multiple Choice: Each is worth two pointsIdentify the letter of the choice that best completes the statement or answers the question.____ 1. The sample statistic s is the point estimator ofa. μbσ.c.d.____ 2. A sample statistic is an unbiased estimator of the population parameter ifa. the expected value of the sample statistic is equal to zerob. the expected value of the sample statistic is equal to onec. the expected value of the sample statistic is equal to thepopulation parameterd. it is equal to zero____ 3. A property of a point estimator that occurs whenever larger sample sizes tend to provide point estimates closer to the population parameter is known asa. efficiencyb. unbiased samplingc. consistencyd. relative estimation____ 4. A random sample of 121 bottles of cologne showed an average content of 4 ounces.It is known that the standard deviation of the contents (i.e., of the population) is 0.22ounces. In this problem the 0.22 isa. a parameterb. a statisticd. the average content of colognes in the long run____ 5. A sample of 92 observations is taken from an infinite population. The sampling distribution of is approximatelya. normal because is always approximately normally distributedb. normal because the sample size is small in comparison to thepopulation sizec. normal because of the central limit theoremd. None of these alternatives is correct.____ 6. 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.____ 7. From a population of 200 elements, a sample of 49 elements is selected. It is determined that the sample mean is 56 and the sample standard deviation is 14. Thestandard error of the mean isa. 3b. 2c. greater than 2d. less than 2____ 8. Which of the following is(are) point estimator(s)?a. σb. μc. sd. α____ 9. A population characteristic, such as a population mean, is calleda. a statistica parameterb.c. a sampledthe mean deviation.____10. The sample statistic, such as , s, or , that provides the point estimate of the population parameter is known asa. a point estimatorb. a parameterc. a population parameterd. a population statistic____11. The fact that the sampling distribution of sample means can be approximated by a normal probability distribution whenever the sample size is large is based on thea. central limit theoremb. fact that we have tables of areas for the normal distributionc. assumption that the population has a normal distributiond. None of these alternatives is correct.____12. Random samples of size 17 are taken from a population that has 200 elements, a mean of 36, and a standard deviation of 8. The mean and the standard deviation ofthe sampling distribution of the sample means area. 8.7 and 1.94b. 36 and 1.94c. 36 and 1.86d. 36 and 8____13. When constructing a confidence interval for the population mean and a small sample is used, the degrees of freedom for the t distribution equalsa. n-1b. nc. 29d. 30_____ 14. The collection of all possible sample points in an experiment isa. the sample spaceb. a sample pointc.an experimentd. the population_____ 15. Of five letters (A, B, C, D, and E), two letters are to be selected at random. How many possible selections are there?a. 20b. 7c. 5!d. 10_____ 16. The “Top Three” at a racetrack consists of picking the correct order of the first three horses in a race. If there are 10 horses in a particular race, how many “Top Three”outcomes are there?a. 302,400b. 720c. 1,814,400d. 10_____ 17. Given that event E has a probability of 0.25, the probability of the complement of event Ea. cannot be determined with the above informationb. can have any value between zero and onec. must be 0.75d. is 0.25_____ 18. The symbol ⋃ shows thea.union of eventsb. intersection of eventsc.sum of the probabilities of eventsd.sample space_____ 19. If P(A) = 0.38, P(B) = 0.83, and P(A ⋂ B) = 0.57; then P(A ⋃ B) =a. 1.21b. 0.64c. 0.78d. 1.78_____ 20. If P(A) = 0.62, P(B) = 0.47, and P(A ⋃ B) = 0.88; then P(A ⋂ B) =a. 0.2914b. 1.9700c. 0.6700d.0.2100_____ 21. If P(A) = 0.85, P(A ⋃ B) = 0.72, and P(A ⋂ B) = 0.66, then P(B) =a. 0.15b. 0.53c. 0.28d. 0.15_____ 22. Two events are mutually exclusive ifa. the probability of their intersection is 1b. they have no sample points in commonc. the probability of their intersection is 0.5d. the probability of their intersection is 1 and they have no sample points in common_____ 23. If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, then P(A ⋂ B) =a. 0.30b. 0.15c. 0.00d. 0.20_____ 24. If A and B are mutually exclusive events with P(A) = 0.3 and P(B) = 0.5, then P(A ⋃ B) =a. 0.00b. 0.15c. 0.8d. 0.2_____ 25. A subset of a population selected to represent the population is aa.subsetb.samplec.small populationd. None of the alternative answers is correct._____ 26. A simple random sample of size n from an infinite population of size N is to be selected. Each possible sample should havea. the same probability of being selectedb. a probability of 1/n of being selectedc. a probability of 1/N of being selectedd. a probability of N/n of being selected_____ 27. A probability distribution for all possible values of a sample statistic is known as aa.sample statisticb.parameterc.simple random sampled.sampling distribution_____ 28. From a population of 200 elements, the standard deviation is known to be 14.A sample of 49 elements is selected. It is determined that the sample mean is 56. The standard error of the mean isa. 3b. 2c. greater than 2d. less than 2_____ 29. From a population of 500 elements, a sample of 225 elements is selected. It is known that the variance of the population is 900. The standard error of the mean is approximatelya. 1.1022b. 2c. 30d. 1.4847Short Answer/ProblemsDirections: Clearly designate your solution to each portion of the questions asked and show your entire work and method for arriving at the solution.1. The sales records of a real estate agency show the following sales over the past 200 days:b. Assign probabilities to the sample points and show their values.c. What is the probability that the agency will not sell any houses in a given day?d. What is the probability of selling at least 2 houses?e. What is the probability of selling 1 or 2 houses?f. What is the probability of selling less than 3 houses?2. Assume two events A and B are mutually exclusive and, furthermore, P(A) = 0.2 and P(B)= 0.4.a. Find P(A ⋂ B).b. Find P(A ⋃ B).c. Find P(A⎜B).3.You are given the following information on Events A, B, C, and D. P(A) = .4, P(B) = .2,P(C) = .1,P(A ⋃ D) = .6, P(A⎜B) = .3, P(A ⋂ C) = .04, P(A ⋂ D) = .03a. Compute P(D).b. Compute P(A ⋂ B).c. Compute P(A⎜C).d. Compute the probability of the complement of C.e. Are A and B mutually exclusive? Explain your answer.f. Are A and B independent? Explain your answer.g. Are A and C mutually exclusive? Explain your answer.h. Are A and C independent? Explain your answer.4. Consider a population of five weights identical in appearance but weighing 1, 3, 5, 7, and 9 ounces.a. Determine the mean and the variance of the population.b. Sampling without replacement from the above population with a sample sizeof 2 produces ten possible samples. Using the ten sample mean values, determinethe mean of the population and the variance of .c. Compute the standard error of the mean.5. A population of 1,000 students spends an average of $10.50 a day on dinner. The standard deviation of the expenditure is $3. A simple random sample of 64 students is taken.a. What are the expected value, standard deviation, and shape of the samplingdistribution of the sample mean?b. What is the probability that these 64 students will spend a combined total of morethan $715.21?c. What is the probability that these 64 students will spend a combined total between$703.59 and $728.45?Solutions to MC Problems1. B 2 C 3. C 4. A 5. C 6. B 7. D 8. C 9. B 10. A11. A 12. C 13. A 14. A 15. D 16. B 17. C 18. A19. B 20. D 21. B 22. B 23. C 24. C 25. B 26. A27. D 28. D 29. DShort Answer/ProblemsDirections: Clearly designate your solution to each portion of the questions asked and show your entire work and method for arriving at the solution.1. ANSWERS:2. ANSWERS:a. 0.0 b. 0.6 c. 0.03ANSWERS:a. 0.23b. 0.06c. 0.4d. 0.9e. No, P(A⎜B) ≠ 0f. No, P(A⎜B) ≠ P(A)g. No, P(A ⋂ C) ≠ 0h. Yes, P(A⎜C) = P(A)4. ANSWERS:a. 5 and 8b. 5 and 3c. 1.7325. ANSWERS:a. 10.5 0.363 normalb. 0.0314c. 0.0794。