智慧树知到《商务统计》章节测试答案

智慧树知到《商务统计》章节测试答案
绪论单元测试
1、Penny Bauer， Chief Financial Officer of Harrison Haulage， suspects irregularities in the payroll system， and orders an inspection of ‘each and every payroll voucher issued since 1 January 2005’.Five per cent of the payroll vouchers contained material errors.This is an example of（）.
A.descriptive statistics
B.nonparametric statistics
C.nominal data
D.inferential statistics
正确答案：descriptive statistics
第一章单元测试
1、Michael Bayley， Marketing Director of UniPower’s Electrical Division， is leading a study to identify and assess the relative importance of product features.Michael directs his staff to design a survey questionnaire for distribution to all of UniPower’s 954 customers.For this study， the set of 954 customers is a（）.
A. sample
B.parameter
C.statistic
D.population
正确答案：population
2、Claudia Taylor， Director of Global Industrial Sales in Melbourne， is concerned by a deteriorating sales trend.Specifically， the number of customers is stable at 1500 but they are purchasing less each year.She orders her staff to search for causes of the downward trend by selecting a focus group of 40 industrial customers.For this study， the set of 40 industrial customers is a（）.
A.statistic
B.population
C.parameter
D.sample
正确答案：sample
3、A politician who is running for the office of premier in a state with 3 million registered voters commissions a survey.In the survey， 53.6% of the 5000 registered voters interviewed say they plan to vote for him.The population of interest is the
A.46.4% of， or 2320， voters interviewed who plan not to vote for him
B.53.6 % of， or 2680， voters interviewed who plan to vote for him
C.5000 registered voters intervieweD.D.3 million registered voters in the state.
正确答案：3 million registered voters in the state.
4、Simon Arnett， Director of Human Resources， is exploring the causes of employee absenteeism at Buderim Bottling during the last operating year（1；January 2005 to 31；December 2005）.The average number of absences per employee， calculated from the personnel data of all employees， is a（）.
A.sample
B.population
C.parameter
D.statistic
正确答案：parameter
5、A summary measure that is computed from a sample to describe a characteristic of the population is called
A.a statistic
B.a parameter
C.Both A and C are correct， since they are the same
D.a population
正确答案：a statistic
6、Simon Arnett， Director of Human Resources， is exploring the causes of employee absenteeism at Buderim Bottling during the last operating year（1；January 2005 to 31；December 2005）.Personnel records of 50 employees are selected for analysis.（The plant employs 250.） For this study， the average number days absent for these 50；employees is a（）.
A.population
B.sample
C.statistic
D.parameter
正确答案：statistic
7、Descriptive statistics deals with methods of
A.doing all of the above
B.summarising data
C.presenting data in a convenient and informative way
D.organising data.
正确答案：doing all of the above
8、Which of the following statements is not true？
A.Statistical inference is used to draw conclusions or inferences about characteristics of populations based on sample data
B.One form of descriptive statistics uses numerical techniques
C.In the language of statistics， the term population refers to a group of people
D.One form of descriptive statistics uses graphical techniques
正确答案：In the language of statistics， the term population refers to a group of people
9、A student achieves an 82 on the first test in a statistics course.From this， she assumes that her average at the end of the semester（after other tests） will be about 82.This is an example of（）.
A.nonparametric statistics
B.descriptive statistics
C.inferential statistics
D.wishful thinking
正确答案：inferential statistics
10、Which of the following is not the goal of descriptive statistics？
A.Summarising data
B.Estimating characteristics of the population
C.Displaying aspects of the collected data
D.
Reporting numerical findings
正确答案：Estimating characteristics of the population
第二章单元测试
1、If data are grouped into intervals and the number of items in each group is listed， this could be called a（）.
A.frequency distribution
B.ogive
C.histogram
D.stem and leaf plot
正确答案：histogram
2、If the individual class frequency is divided by the total frequency， the result is the（）.
A.stem and leaf plot
B.relative frequency
C.midpoint frequency
D.cumulative frequency
正确答案：relative frequency
3、A cumulative frequency polygon is also called（）.
A.a frequency polygon
B.a stem and leaf plot
C.an ogive
D.a histogram
正确答案：an ogive
4、The number of class intervals in a frequency distribution is usually between（）.
A.3 and 5
B.1 and 25
C.7 and 9
D.5 and 15
正确答案：5 and 15
5、One advantage of a stem and leaf plot over a frequency distribution is that（）.
A.the class midpoints are used as the leaf
B.the class midpoints are used as the stem
C.it contains more class intervals
D.the values of the original data are retained
正确答案：the values of the original data are retained
6、One rule that must always be followed in constructing frequency distributions is that（）.
A.each data point can only fall into one class
B.the width of each class is equal to the range
C.the number of classes must be less than 10
D.the number of intervals must be an odd number
正确答案：each data point can only fall into one class
7、Which of the following is best to show the percentage of a total budget that is spent on each category of items？
A.histogram
B.ogive
C.stem and leaf chart
D.pie chart
正确答案：pie chart
8、A cumulative frequency distribution would provide（）.
A.a running total of the frequencies in the classes
B.the proportion of the total frequencies which fall into each class
C.a very cloudy picture of the frequencies
D.a graph of a frequency distribution
正确答案：a running total of the frequencies in the classes
9、The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developeD.Class IntervalFrequency20-under 403040-under 604560-under 808080-under 10045
What is the cumulative frequency of the third class？
A.75
B.80
C.0.40
D.155
正确答案：155
10、The number of phone calls arriving at a switchboard each hour has been recorded and the following frequency distribution has been developeD.Class IntervalFrequency20-under 403040-under 604560-under 808080-under 10045
What is the approximate range of the number of phone calls arriving each hour？
A.20
B.200
C.100
D.80
正确答案：80
第三章单元测试
1、Simon Arnett， Director of Human Resources， is exploring employee absenteeism at the Buderim Bottling during the last operating year.A sample of six personnel records produced the following dat
A.0， 2， 4， 7， 2， 9.The variance of the number absences per employee is（）.
A.3.41
B.3.11
C.9.67
D.11.6
正确答案：11.6
2、Jessica Salas， Managing Director of Salas Products， is reviewing the warranty policy for her company’s new model of car batteries.Life tests performed on a sample of 100 batteries indicate
D.（1） an average life of 75 months，（2） a standard deviation of 5 months， and（3） battery life is approximately normally distributed.Approximately 68% of the batteries will last between（）.
A.60 and 90 months
B.65 and 85 months
C.55 and 95 months
D.70 and 80 months
正确答案：70 and 80 months
3、The average starting salary for graduates at a university is $25，000 with a standard deviation of $2000.A histogram of the data shows the shape to be very erratic so Chebyshev’s Theorem should be used.How many of the graduates would have a starting salary between 21，000 and 29，000？
A.at least 75%
B.at least 89%
C.at least 68%
D.at least 95%
正确答案：at least 75%
4、The sample standard deviation is found by taking the square root of（）.
A.the sample variance
B.the coefficient of variation
C.the sample mean
D.the mean absolute deviation
正确答案：the sample variance
5、The number of standard deviations that a value（X） is above or below the mean is the（）.
A.interquartile range
B.absolute deviation
C.coefficient of variation
D.Z score
正确答案：Z score
6、In a histogram， the proportion of the total area that must be to the left of the median is（）
A.exactly 0.50.
B.less than 0.50 if the distribution is skewed to the left
C.more than 0.50 if the distribution is skewed to the right
D.between 0.25 and 0.60 if the distribution is symmetric and unimodal
正确答案：exactly 0.50.
7、Which of the following is NOT a measure of central tendency？
A.mode
B.median
C.variance
D.mean
正确答案：variance
8、Another term for average is（）.
A.mean
B.mode
C.median
D.variance
正确答案：mean
9、If the mean of a distribution is greater than the median， then the distribution is（）.
A.symmetrical about its mean
B.skewed to the right
C.skewed to the left
D.not skewed
正确答案：skewed to the right
10、The mean is not affected by the extreme values.。
A.正确
B.错误
正确答案：错误
第四章单元测试
1、A process that produces outcomes is called（）.
A.an event
B.a result
C.an experiment
D.population equivalent
正确答案：an experiment
2、Which of the following is NOT a legitimate probability value？
A.15/16
B.0.23
C.0.67
D.4/3
正确答案：4/3
3、An outcome of an experiment is called（）.
A.an event
B.a probability
C.a complement
D.a priori elements
正确答案：an event
4、The list of all elementary events for an experiment is called（）.
A.the exhaustive list
B.the population space
C.the sample space
D.the event union
正确答案：the sample space
5、If A and B are mutually exclusive events with P（A） = 0.70， then P（B）：（）
A.can take any value between 0 and 0.70
B.cannot be determined from the information given
C.cannot be larger than 0.30
D.can take any value between 0 and 1
正确答案：cannot be larger than 0.30
6、If an event is in set X but is not in set Y， which of the following is true？
A.it is in both the union and intersection of X and Y
B.it is in the union of X and Y
C.it is in the intersection of X and Y
D.it is not in the union of X and Y
正确答案：it is in the union of X and Y
7、If the occurrence of one event does not affect the occurrence of another event， then the two events are（）.
A.independent
B.mutually exclusive
C.elementary events
D.complements
正确答案：independent
8、Let A be the event that a student is enrolled in an accounting course， and let S be the event that a student is enrolled in a statistics course.It is known that 30% of all students are enrolled in an accounting course and 40% of all students are enrolled in statistics.Included in these numbers are 15% who are enrolled in both statistics and accounting.Find P（S）.
A.0.15
B.0.40
C.0.30
D.0.55
正确答案：0.40
9、Given P（A） = 0.40， P（B） = 0.50， P（A ；B） = 0.15.Which of the following is true？
A.A and B are mutually exclusive
B.A and B are not independent
C.A and B are independent
D.A and B are collectively exhaustive
正确答案：A and B are not independent
10、Meagan Davies manages a portfolio of 200 common stocks.Her staff classified the portfolio stocks by ‘industry sector’ and ‘investment objective’.InvestmentIndustry Sector
ObjectiveElectronicsAirlinesHealthcareTotalGrowth1001040150Income20201050Total1203050200；Which of the following is NOT true？
A.Electronics and Growth are dependent.
B.Growth and Income are complementary events.
C.Airlines and Healthcare are collectively exhaustive.
D.Electronics and Healthcare are mutually exclusive.
正确答案：Airlines and Healthcare are collectively exhaustive.
第五章单元测试
1、Variables which take on values only at certain points over a given interval are called（）.
A.continuous random variables
B.value variables
C.discrete random variables
D.point variables
正确答案：discrete random variables
2、A variable that can take on values at any point over a given interval is called（）.
A.a continuous random variable
B.a discrete random variable
C.a value variable
D.a point variable
正确答案：a continuous random variable
3、You are offered an investment opportunity.Its outcomes and probabilities are presented in the following table.XP（X）–$1000.40$0.20+$1000.40；The mean of this distribution is（）.
A.–$400
B.$400
C.$200
D.$0
正确答案：$0
4、You are offered an investment opportunity.Its outcomes and probabilities are presented in the following table.XP（X）–$1000.40$0.20+$1000.40；The standard deviation of this distribution is（）.
A.$800，000
B.$894
C.$663
D.–$400
正确答案：$894
5、The long-run average or mean of a Poisson distribution is usually referred to as（）.
A.s
B.m
C.l
D.a
正确答案：l
6、The variance of a Poisson distribution is equal to（）.
A.l/2
B.
C.l
D.l2
正确答案：l
7、If X is a binomial random with n；= 8 and p；= 0.6， what is the probability that X is less than or equal to 2？
A.0.009
B.0.050
C.0.041
D.0.375
正确答案：0.050
8、If X is a binomial random with n；= 8 and p；= 0.6， what is the probability that X is greater than 2？
A.0.950
B.0.991
C.0.011
D.0.124
正确答案：0.950
9、Twenty-five items are sampled.Each of these has the same probability of being defective.The probability that exactly 2 of the 25 are defective could best be found by（）.
A.using the binomial distribution
B.using the Poisson distribution
C.using the normal distribution
D.using the exponential distribution
正确答案：using the binomial distribution
10、You are offered an investment opportunity.Its outcomes and probabilities are presented in the following table.XP（X）–$1000.40$0.20+$1000.40；Which of the following statements is true？
A.This distribution is skewed to the left.
B.This is a binomial distribution.
C.This distribution is skewed to the right.
D.This distribution is symmetric.
正确答案：This distribution is symmetric.
第六章单元测试
1、The normal distribution is an example of（）.
A.a continuous distribution
B.an exponential distribution
C.a bimodal distribution
D.a discrete distribution
正确答案：a continuous distribution
2、The total area underneath any normal curve is（）.
A.equal to the coefficient of variation
B.equal to the mean
C.equal to the variance
D.equal to 1
正确答案：equal to 1
3、The area to the left of the mean in any normal distribution is（）.
A.equal to 1
B.equal to 0.5
C.equal to the mean
D.equal to the variance
正确答案：equal to 0.5
4、For any normal distribution， any value less than the mean would have a（）.
A.negative probability of occurring
B.negative z-score
C.negative variance
D.positive z-score
正确答案：negative z-score
5、A standardised normal distribution has the following characteristics：
A.he mean and variance are both equal to 1
B.the mean and variance are both equal to 0
C.the mean is equal to 0 and the variance is equal to 1
D.the mean is equal to the variance
正确答案：the mean is equal to 0 and the variance is equal to 1
6、If X is a normal random variable with mean 80 and standard deviation 5， calculate the z-score if X = 88.
A.-1.6
B.1.8
C.-1.8
D.1.6
正确答案：1.6
7、Suppose X is a normal random variable with mean 60 and standard deviation 2.A z-score was calculated for a number， and the z-score；is 3.4.What is x？
A.56.6
B.63.4
C.66.8
D.53.2
正确答案：66.8
8、Let X be a normal random variable with mean 20 and standard deviation 4.Find P（16 <； X <；22）.
A.0.0328
B.0.5328
C.0.1498
D.0.4672
正确答案：0.5328
9、Let X be a normal random variable with mean 20 and standard deviation 4.The 90th percentile of X is（）.
A.26.579
B.20.000
C.22.698
D.25.126
正确答案：25.126
10、A z-score；is the number of（）that a value is from the mean.
A.units
B.standard deviations
C.miles
D.variances
正确答案：standard deviations
第七章单元测试
1、As a general rule， the normal distribution is used to approximate the sampling distribution of the sample mean only if
A.the sample size n；is sufficiently large
B.np；and n（1 – p） are both greater than 5
C.the underlying population is normal
D.the sample mean is close to 0.50.
正确答案：the sample size n；is sufficiently large
2、The eight employees of the Art Department and their ‘years of experience’ are listed in the following table.EmployeeABCDEFGHExperience（years）1021115748；If a sample of three employees is selected with replacement， the number of elementary outcomes in the sample space is（）.
A.56
B.512
C.336
D.64
正确答案：512
3、A sampling distribution is a distribution of（）.
A.a sample statistic， such as，
4、The standard deviation of a sampling distribution is commonly called（）.
A.the standard error.
B.the uniform spreaD.C.statistical margin.
D.statistical leverage.
正确答案：the standard error.
5、The central limit theorem states that if n；is large enough， the distribution of the sample means is（）distributed regardless of the shape of the population.
A.approximately normally
B.nonrandomly
C.uniformly
D.randomly
正确答案：approximately normally
6、According to the central limit theorem， the mean of the sample means for a given size of sample is equal to（）.
A.the population mean
B.the population mean divided by the square root of n
C.zero
D.the population mean divided by n
正确答案：the population mean
7、Increasing the sample size causes the standard error of the mean to（）.
A.decrease in value
B.destabilise in value
C.seek market equilibrium
D.increase in value
正确答案：decrease in value
8、Increasing the sample size causes the sampling distribution of；to（）.
A.have less dispersion
B.shift to the left
C.shift to the right
D.have more dispersion
正确答案：have less dispersion
9、Suppose a population has a mean of 90 and a standard deviation of 28.If a random sample of size 49 is drawn from the population， the probability of drawing a sample with a mean of more than 95 is（）.
A.0.1056
B.0.4286
C.0.3944
D.0.8944
正确答案：0.1056
10、Suppose 40% of all university students have a computer at home and a sample of 64 is taken.What is the probability that more than 30 of those in the sample have a computer at home？
A.0.1314
B.0.3686
C.0.6314
D.0.8686
正确答案：0.1314
第八章单元测试
1、When a range of values is used to estimate a population parameter， it is called（）.
A.an interval estimate
B.a range estimate
C.a point estimate
D.a statistical parameter
正确答案：an interval estimate
2、Catherine Cho， Director of Marketing Research at Vitalglow Pty Ltd， is evaluating consumer acceptance of a new toothpaste package.Her staff report that 17% of a random sample of 200 Darwin households prefer the new package to all other package designs.If Catherine concludes that 17% of all households prefer the new package， she is using a（）.
A.a statistical parameter
B.an interval estimate
C.a range estimate
D.a point estimate
正确答案：a point estimate
3、The z-value；associated with a two-sided 90% confidence interval is（）.
A.1.28
B.1.96
C.1.645
D.2.575
正确答案：1.645
4、Suppose a random sample of 36 is selected from a population with a standard deviation of 12.If the sample mean is 98， the 99% confidence interval to estimate the population mean is（）.
A.92.85 to 103.15
B.97.35 to 98.65
C.94.08 to 101.92
D.93.34 to 102.66
正确答案：93.34 to 102.66
5、Sam Gates， Marketing Director of Mansfield Motors’ Electrical Division， is leading a study to assess the relative importance of product features.An item on a survey questionnaire distributed to 121 Mansfield customers asked them to rate the importance of ‘ease of maintenance’ on a scale of 1 to 10（with 1 meaning ‘not important’ and 10 meaning ‘highly important’）.His staff assembled the following statistics.
Ease of MaintenanceMean7.5Population Standard Deviation 1.1The 90% confidence interval for the population mean rating of ‘ease of maintenance’ is（）.
A.7.30 to 7.70
B.7.34 to 7.66
C.5.69 to 9.31
D.5.34 to 9.66
正确答案：7.34 to 7.66
6、A researcher wants to estimate the proportion of the population which possess a given characteristic.A random sample of size 600 is taken resulting in 330 items which possess the characteristic.The point estimate for this population proportion is（）.
A.0.60
B.0.33
C.0.55
D.0.45
正确答案：0.55
7、The t-distribution is similar to a normal distribution.However the t-distribution is（）.
A.bimodal
B.discrete
C.flatter
D.not symmetric
正确答案：flatter
8、In order to find values in the t-；distribution table， you must convert the sample size or sizes to（）.
A.student values
B.population sizes
C.degrees of freedom
D.z-values
正确答案：degrees of freedom
9、If the degrees of freedom in a t-distribution become very large，（）.
A.the sample size must be very small
B.the sample mean approaches zero
C.the t-values and the z-values are almost the same
D.the population size must be very large
正确答案：the t-values and the z-values are almost the same
10、In finding a confidence interval for the population mean， the population standard deviation should be used if it is known.If the population standard deviation is not known， then it should be estimated with（）.
A.the sample variance
B.the mean
C.the sample standard deviation
D.the range
正确答案：the sample standard deviation
第九章单元测试
1、The first step in testing a hypothesis is to establish（）.
A.a power function
B.an indirect hypothesis
C.a null hypothesis and alternative hypothesis
D.a not rejectance hypothesis and a rejection hypothesis
正确答案：a null hypothesis and alternative hypothesis
2、Consider the following null and alternative hypotheses.Ho：m； <；=7H
A.m；>； 6These hypotheses（）.
A.are not collectively exhaustive
B.are established correctly
C.are not mutually exclusive
D.do not reference a population parameter
正确答案：are not mutually exclusive
3、Consider the following null and alternative hypotheses.
Ho：m >；=；7
H
A.m；<； 6
These hypotheses（）.
A.are established correctly
B.do not reference a population parameter
C.are not collectively exhaustive
D.are not mutually exclusive
正确答案：are not collectively exhaustive
4、Consider the following null and alternative hypotheses.Ho：；>； 352
These hypotheses（）.
A.are established correctly
B.do not reference a population parameter
C.are not collectively exhaustive
D.are not mutually exclusive
正确答案：do not reference a population parameter
5、The region of the distribution in hypothesis testing in which the null hypothesis is rejected is called the（）.
A.alternative region
B.null region
C.rejection region
D.not rejectance region
正确答案：rejection region
6、The rejection and not rejectance regions are divided by a point called the（）.
A.critical value
B.dividing point
C.rejection value
D.not rejectance value
正确答案：critical value
7、The probability of committing a Type II error is represented by（）.
A.a；/ 2
B.a
C.1 – a
D.b
正确答案：b
8、Jennifer Cantu， Customer Services Manager at Tri-Nation Auto Insurance， monitors the claims processing time of the claims division.Her standard includes ‘a mean processing time of 5 days or less’.Each week， her staff checks for compliance by analysing a random sample of 60 claims.Jennifer’s alternative hypothesis is（）.
A.5
B.n；= 60
C.>； 5
D.<； 5
正确答案：>； 5
9、The manufacturers of a deodorant claim that the mean drying time of their product is， at most， 15 minutes.A sample consisting of 16 cans of the product was used to test the manufacturer’s claim.The experiment yielded a mean drying time of 18 minutes with a standard deviation of 6 minutes.Test the claim at the 0.05 significance level.
A.Computed test statistic = 2 and is greater than 1.753， so reject H0：µ = 15.
B.Computed test statistic = 2 and is greater than 1.645， so reject H0：µ ≤ 15.
C.Computed test statistic = 2 and is greater than 2.131， so reject H0：µ ≤ 15.
D.Computed test statistic = 2 and is greater than 1.96， so reject H0：µ ≤ 15.
正确答案：Computed test statistic = 2 and is greater than 1.753， so reject H0：µ = 15.
10、What happens to the rejection region if the level of significance is changed from 0.10 to 0.05？
A.it gets larger
B.it gets smaller
C.it does not change
正确答案：it gets smaller
第十章单元测试
1、Restaurateur， Daniel Valentine， is evaluating two sites， Port Douglas and Mission Beach， for his next restaurant.He wants to prove that Port Douglas residents（population 1） dine out more often than Mission Beach residents（population 2）.Denny plans to test this hypothesis using a random sample of 81 families from each town.His null hypothesis is（）.
A.s12；<； s22
B.m1；– m2；= 0
C.p1；– p2；= 0
D.m1 – m2 >； 0
正确答案：m1；– m2；= 0
2、A researcher wants to estimate the difference in the means of two populations.A random sample of 36 items from the first population results in a sample mean of 430.A random sample of 49 items from the second population results in a sample mean of 460.The population standard deviations are 120 for the first population and 140 for the second population.From this information， a point estimate of the difference of population means can be calculated as（）.
A.43
B.46
C.-30
D.-13
正确答案：-30
3、A researcher wants to estimate the difference in the means of two populations.A random sample of 36 items from the first population results in a sample mean of 430.A random sample of 49 items from the second population results in a sample mean of 460.The population standard deviations are 120 for the first population and 140 for the second population.From this information， a 95% confidence interval for the difference in population means is（）.
A.–76.53 to 16.53
B.–95.90 to 35.90
C.–102.83 to 42.43
D.85.44 to 25.44
正确答案：85.44 to 25.44
4、A researcher is interested in testing to determine if the mean of population one is greater than the mean of population two.The null hypothesis is that there is no difference in the population means（i.e.the difference is zero）.The alternative hypothesis is that there is a difference（i.e.the difference is not equal to zero）.He randomly selects a sample of 9 items from population one resulting in a mean of 14.3 and a standard deviation of 3.4.He randomly selects a sample of 14 items from population two resulting in a mean of 11.8 and a standard deviation 2.9.He is using an alpha value of .10 to conduct this test.Assuming that the populations are normally distributed， the degrees of freedom for this problem are（）.
A.2
B.23
C.22
D.21
正确答案：21
5、A researcher wants to conduct a before/after study on 11 subjects to determine if a treatment results in any difference in scores.The null hypothesis is that the average difference is zero while the alternative hypothesis is that the average difference is not zero.Scores are obtained on the subjects both before and after the treatment.After subtracting the after scores from the before scores， the average difference is calculated to be –2.40 with a sample standard deviation of 1.21.Assume that the differences are normally distributed in the population.The degrees of freedom for this test are（）.
A.11
B.20
C.9
D.10
正确答案：10
6、A researcher is performing a two-tailed related samples（matched pairs） t-test.A total of 12 people are in the sample， and before and after measures are taken.The observed t-value；for this is –1.84.The level of significance is 0.05.The correct decision is to（）.
A.use the z-table instead of the t-table
B.do not reject the null hypothesis
C.reject the null hypothesis
D.take a larger sample
正确答案：do not reject the null hypothesis
7、Stefan Irwin， Marketing Manager at Classic Merchandise， is investigating response rates to scented and unscented direct mail catalogues.If the response rate for the scented catalogue（population 1） is higher， Mike will adopt the scented version.His staff randomly selects two samples of 200 each from the company’s customer database.One month after the 400 test catalogues were mailed， forty-five orders（twenty-five from the scented and twenty from the unscented） were received from the test catalogues.Assuming a ；= .01， Mike’s alternate hypothesis is（）.
A.p1；– p2；>； 0
B.s12；<； s22
C.m1；– m2；= 0
D.m1 – μ2；≠ 0
正确答案：p1；– p2；>； 0
8、Cowra Construction Company purchases steel rods for its projects.Based on previous tests， Clarrie Carter， Quality Assurance Manager， has recommended purchasing rods from Redding Rods（population 1）， rather than Stockton Steel（population 2）， since Redding’s rods had less variability in length.Recently， Stockton revised it rod shearing operation， and Clarrie has sampled the outputs from Redding’s and Stockton’s rod manufacturing processes.The results for Redding were s12；= 0.10 with n1；= 8， and， for Stockton， the results were s22；= 0.05 with n2；= 10.Assume that rod lengths are normally distributed in the population.Clarrie’s alternate hypothesis is（）.
A.s12 <； s22
B.s12 ≠ s22
C.s12 >； s22
D.s12 ；= s22
正确答案：s12 >； s22
9、Tamara Hill， Fund Manager with Hillcrest Value Fund， manages a portfolio of 250 common stocks.Tamara is searching for a ‘low risk’ issue to add to the portfolio， i.e.one with a price variance less than that of the S&；P 500 index.Moreover， she assumes an issue is not ‘low risk’ until demonstrated otherwise.Her staff reported that during the last nine quarters the price variance for the S&；P 500 index（population 1） was 25， and for the last seven quarters the price variance for XYC common（population 2） was 8.Assume that stock prices are normally distributed in the population.Using a = 0.05， the appropriate decision is（）.
A.do not reject the null hypothesis s12 ；= ；s22
B.reject the null hypothesis s12 ；= ；s22
C.eject the null hypothesis s12 ；¹ ；s22
D.do not reject the null hypothesis s12 ；¹ ；s22
正确答案：do not reject the null hypothesis s12 ；= ；s22
10、Cindy Ho， Finance Manager at Red Hill Radiator Supplies（RHRS）， theorises that the discount level offered to credit customers affects the average collection period on credit sales.Accordingly， she has designed an experiment to test her theory using four sales discount rates（0%， 2%， 4% and 6%） by randomly assigning five customers to each sales discount rate.An analysis of Cindy’s data produced the following ANOVA table.Source of VariationSSdfMSFTreatment5.3531.783333
Error177.21611.075
Total182.5519
Using a；= 0.01， the appropriate decision is（）.
A.do not reject the null hypothesis m1；= m2；= m3；= m4
B.do not reject the null hypothesis m1；≠ m2；≠ m3；≠m4
C.reject the null hypothesis m1；= m2；= m3；= m4
D.reject the null hypothesis m1；≠ m2；≠ m3；≠ m4
正确答案：do not reject the null hypothesis m1；= m2；= m3；= m4
第十一章单元测试
1、For the same set of observations on a specified dependent variable， two differentindependent variables were used to develop 2 simple linear regression models.The results are summarized as follows：Based on the above results， we can conclude that
A.the total variation is different for Model I and Model II.
B.the SSE for Model II is smaller than the SSE for Model I.
C.a prediction based on Model I is likely better than a prediction based on Model II.
D.a prediction based on Model II is likely better than a prediction based on Model I.
正确答案：a prediction based on Model I is likely better than a prediction based on Model II.
2、A regression analysis between sales（in $1000） and advertising（in $100） yielded the least squares line= 75 + 6x.；This implies that if $800 is spent on advertising， then the predicted amount of sales（in dollars） is
A.$123，000
B.$4，875
C.$487，500
D.$12，300
正确答案：$123，000
3、The following results were obtained from a simple regression analysis：= 37.2895 – 1.2024x；r2；= 0.6744 and s2；= 0.2934 ；For each unit change in x， the estimated change in the average；value of y；is equal to
A.-1.2024
B.37.289
C.0.6744
D.0.2934
正确答案：-1.2024
4、A regression analysis between sales（in $1，000） and advertising（in $） yielded the least square line ；= 80，000 + 5x；This implies that an
A.increase of $1 in advertising is expected to result in an increase of $5 in sales.
B.increase of $1 in advertising is expected to result in an increase of $5，000 in sales.
C.increase of $5 in advertising is expected to result in an increase of $5，000 in sales.
D.increase of $1 in advertising is expected to result in an increase of $80，005 in sales.
正确答案：increase of $1 in advertising is expected to result in an increase of $5，000 in sales.
5、The point estimate of the variance of the error term in a regression model is
A.MSE
B.
D.SSE
正确答案：MSE
6、In a regression problem， if the coefficient of determination is 0.95， this means that：
A.95% of the y values are positive.
B.95% of the x values are equal.
C.95% of the variation in x can be explained by the variation in y.
D.95% of the variation in y can be explained by the variation in x.
正确答案：95% of the variation in y can be explained by the variation in x.
7、In regression analysis， the residuals represent th
E.
A.difference between the actual y values and their predicted values.
B.square root of the coefficient of determination.
C.difference between the actual x values and their predicted values.
D.change in y per unit change in x.
正确答案：difference between the actual y values and their predicted values.
8、In the simple linear regression model， the population parameters of the y-intercept and the slope are estimated by：
A.
9、If the standard error of estimate；= 20 and n = 10， then the sum of squares for error， SSE， is：
A.4000
B.400
C.3200
D.40，000
正确答案：3200
10、Which of the following statistics and procedures can be used to determine whether a linear model should be employed？
A.The standard error of estimate.
B.All of the above are correct answers.
C.The t-test of the slope.
D.The coefficient of determination.
正确答案：All of the above are correct answers.