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.。
