商務(wù)統(tǒng)計(jì)學(xué)筆試復(fù)習(xí)習(xí)題

1、一、 The manager of the customer service division of a major consumer electronics company is interested in determining whether the customers who have purchased a videocassette recorder made by the company over the past 12 months are satisfied with their products. 1. , the population of interest isa) a

2、ll the customers who have bought a videocassette recorder made by the company over the past 12 months.b) all the customers who have bought a videocassette recorder made by the company and brought it in for repair over the past 12 months.c) all the customers who have used a videocassette recorder ove

3、r the past 12 months.d) all the customers who have ever bought a videocassette recorder made by the company.ANSWER:a2. , which of the following will be a good frame for drawing a samplea) Telephone directory.b) Voting registry.c) The list of customers who returned the registration card.d) A list of

4、potential customers purchased from a database marketing company.ANSWER:c3. the possible responses to the question "How many videocassette recorders made by other manufacturers have you used" are values from aa) discrete random variable.b) continuous random variable.c) categorical random va

5、riable.d) parameter.ANSWER:a4. the possible responses to the question "Are you happy, indifferent, or unhappy with the performance per dollar spent on the videocassette recorder" are values from aa) discrete numerical random variable.b) continuous numerical random variable.c) categorical r

6、andom variable.d) parameter.ANSWER:cTYPE: MC DIFFICULTY: EasyKEYWORDS: categorical random variable, types of data5. the possible responses to the question "What is your annual income rounded to the nearest thousands" are values from aa) discrete numerical random variable.b) continuous nume

7、rical random variable.c) categorical random variable.d) parameter.ANSWER:a6. the possible responses to the question "How much time do you use the videocassette recorder every week on the average" are values from aa) discrete numerical random variable.b) continuous numerical random variable

8、.c) categorical random variable.d) parameter.ANSWER:b7. the possible responses to the question "How many people are there in your household" are values from aa) discrete numerical random variable.b) continuous numerical random variable.c) categorical random variable.d) parameter.ANSWER:a8.

9、 the possible responses to the question "How would you rate the quality of your purchase experience with 1 = excellent, 2 = good, 3 = decent, 4 = poor, 5 = terrible" are values from aa) discrete numerical random variable.b) continuous numerical random variable.c) categorical random variabl

10、e.d) parameter.ANSWER: c9. the possible responses to the question "What brand of videocassette recorder did you purchase" are values from aa) discrete numerical random variable.b) continuous numerical random variable.c) categorical random variable.d) parameter.ANSWER:c10. the possible resp

11、onses to the question "Out of a 100 point score with 100 being the highest and 0 being the lowest, what is your satisfaction level on the videocassette recorder that you purchased" are values from aa) discrete numerical random variable.b) continuous numerical random variable.c) categorical

12、 random variable.d) parameter.ANSWER:a11. the possible responses to the question "In which year were you born" are values from aa) discrete numerical random variable.b) continuous numerical random variable.c) categorical random variable.d) parameter.ANSWER:a二、The chancellor of a major univ

13、ersity was concerned about alcohol abuse on her campus and wanted to find out the proportion of students at her university who visited campus bars on the weekend before the final exam week. Her assistant took a random sample of 250 students. The total number of students in the sample who visited cam

14、pus bars on the weekend before the final exam week is an example of e) a categorical random variable.f) a discrete random variable.g) a continuous random variable.h) a parameter. ANSWER:b三、 The chancellor of a major university was concerned about alcohol abuse on her campus and wanted to find out th

15、e proportion of students at her university who visited campus bars on the weekend before the final exam week. Her assistant took a random sample of 250 students and computed the portion of students in the sample who visited campus bars on the weekend before the final exam. The portion of all student

16、s at her university who visited campus bars on the weekend before the final exam week is an example of i) a categorical random variable.j) a discrete random variable.k) a continuous random variable.l) a parameter.ANSWER:d四、 The chancellor of a major university was concerned about alcohol abuse on he

17、r campus and wanted to find out the proportion of students at her university who visited campus bars on the weekend before the final exam week. Her assistant took a random sample of 250 students. The portion of students in the sample who visited campus bars on the weekend before the final exam week

18、is an example of _.m) a categorical random variable.n) a discrete random variable.o) a parameter.p) a statisticANSWER:d五、The ordered array below resulted from taking a sample of 25 batches of 500 computer chips and determining how many in each batch were defective.Defects124455679912121517 20 212323

19、252627272829291. Referring to Table 2-11, if a frequency distribution for the defects data is constructed, using "0 but less than 5" as the first class, the frequency of the “20 but less than 25” class would be _.ANSWER:42. Referring to Table 2-11, if a frequency distribution for the defec

20、ts data is constructed, using "0 but less than 5" as the first class, the relative frequency of the “15 but less than 20” class would be _.ANSWER: or 8% or 2/253. Referring to Table 2-11, construct a frequency distribution for the defects data, using "0 but less than 5" as the fi

21、rst class.ANSWER:Defects Frequency0 but less than 5 45 but less than 10 610 but less than 15 215 but less than 20 220 but less than 25 425 but less than 30 74. Referring to Table 2-11, construct a relative frequency or percentage distribution for the defects data, using "0 but less than 5"

22、 as the first class.ANSWER:Defects Percentage0 but less than 5 165 but less than 10 2410 but less than 15 815 but less than 20 820 but less than 25 1625 but less than 30 285. Referring to Table 2-11, construct a cumulative percentage distribution for the defects data if the corresponding frequency d

23、istribution uses "0 but less than 5" as the first class.ANSWER:Defects CumPct005161040154820562572301006. Referring to Table 2-11, construct a histogram for the defects data, using "0 but less than 5" as the first class.ANSWER:7. Referring to Table 2-11, construct a cumulative pe

24、rcentage polygon for the defects data if the corresponding frequency distribution uses "0 but less than 5" as the first class.ANSWER:六、Health care issues are receiving much attention in both academic and political arenas. A sociologist recently conducted a survey of citizens over 60 years

25、of age whose net worth is too high to qualify for Medicaid and have no private health insurance. The ages of 25 uninsured senior citizens were as follows:606162636465666868697073737475767681818286878990921. Referring to Table 3-1, calculate the arithmetic mean age of the uninsured senior citizens to

26、 the nearest hundredth of a year.ANSWER: years2. Referring to Table 3-1, identify the median age of the uninsured senior citizens.ANSWER:73 years3. Referring to Table 3-1, identify the first quartile of the ages of the uninsured senior citizens.ANSWER: years4. Referring to Table 3-1, identify the th

27、ird quartile of the ages of the uninsured senior citizens.ANSWER: years5. Referring to Table 3-1, identify the interquartile range of the ages of the uninsured senior citizens.ANSWER:16 years6. Referring to Table 3-1, identify which of the following is the correct statement.a) One fourth of the seni

28、or citizens sampled are below years of age.b) The middle 50% of the senior citizens sampled are between and years of age.c) The average age of senior citizens sampled is years of age.d) All of the above are correct.ANSWER:a7. Referring to Table 3-1, identify which of the following is the correct sta

29、tement.a) One fourth of the senior citizens sampled are below 64 years of age.b) The middle 50% of the senior citizens sampled are between and years of age.c) 25% of the senior citizens sampled are older than years of age.d) All of the above are correct.ANSWER:c8. Referring to Table 3-1, what type o

30、f shape does the distribution of the sample appear to haveANSWER:Slightly positive or right-skewed.9. Referring to Table 3-1, calculate the variance of the ages of the uninsured senior citizens correct to the nearest hundredth of a year squared.ANSWER: years210. Referring to Table 3-1, calculate the

31、 standard deviation of the ages of the uninsured senior citizens correct to the nearest hundredth of a year.ANSWER: years11. Referring to Table 3-1, calculate the coefficient of variation of the ages of the uninsured senior citizens.ANSWER:%七、The stem-and-leaf display below represents the number of

32、cargo manifests approved by customs inspectors of the Port of New York in a sample of 35 days. STEMLEAVES1H678892L0042H993L1122Note (1):1H means the “high teens” 15, 16, 17, 18, or 19; 2L means the “l(fā)ow twenties” 20, 21, 22, 23, or 24; 2H means the “high twenties” 25, 26, 27, 28, or 29, etc. Note (2

33、):For this sample, the sum of the observations is 838, the sum of the squares of the observations is 20,684, and the sum of the squared differences between each observation and the mean is . 1. Referring to Table 3-4, the arithmetic mean of the customs data is _.ANSWER:2. Referring to Table 3-4, the

34、 median of the customs data is _.ANSWER:233. Referring to Table 3-4, the first quartile of the customs data is _.ANSWER:214. Referring to Table 3-4, the third quartile of the customs data is _.ANSWER:275. Referring to Table 3-4, the range of the customs data is _.ANSWER:166. Referring to Table 3-4,

35、the interquartile range of the customs data is _.ANSWER:67. Referring to Table 3-4, the variance of the customs data is _.ANSWER:8. Referring to Table 3-4, the standard deviation of the customs data is _.ANSWER:9. Referring to Table 3-4, the coefficient of variation of the customs data is _ percent.

36、ANSWER:% or 18%10. Referring to Table 3-4, the five-number summary for the data in the customs sample consists of _, _, _, _, _.ANSWER:16, 21, 23, 27, 3211. Referring to Table 3-4, construct a boxplot of this sample. ANSWER:八、Times spent studying by students in the week before final exams follow a n

37、ormal distribution with standard deviation 8 hours. A random sample of 4 students was taken in order to estimate the mean study time for the population of all students.1. what is the probability that the sample mean exceeds the population mean by more than 2 hoursANSWER:2. what is the probability th

38、at the sample mean is more than 3 hours below the population meanANSWER:3. what is the probability that the sample mean differs from the population mean by less than 2 hoursANSWER: using Excel or using Table 4. what is the probability that the sample mean differs from the population mean by more tha

39、n 3 hoursANSWER: using Excel or using Table 九、A quality control engineer is interested in the mean length of sheet insulation being cut automatically by machine. The desired length of the insulation is 12 feet. It is known that the standard deviation in the cutting length is feet. A sample of 70 cut

40、 sheets yields a mean length of feet. This sample will be used to obtain a 99% confidence interval for the mean length cut by machine.1. Referring to Table 8-3, the critical value to use in obtaining the confidence interval is _.ANSWER:2. Referring to Table 8-3, the confidence interval goes from _ t

41、o _.ANSWER: to 3. True or False: Referring to Table 8-3, the confidence interval indicates that the machine is not working properly.ANSWER:True4. True or False: Referring to Table 8-3, the confidence interval is valid only if the lengths cut are normally distributed.ANSWER:FalseEXPLANATION: With a s

42、ample size of 70, this confidence interval will still be valid if the lengths cut are not normally distributed due to the central limit theorem.KEYWORDS: confidence interval, mean, standardized normal distribution, central limit theorem5. Referring to Table 8-3, suppose the engineer had decided to e

43、stimate the mean length to within with 99% confidence. Then the sample size would be _.ANSWER: rounds up to 166十、A manager of the credit department for an oil company would like to determine whether the average monthly balance of credit card holders is equal to $75. An auditor selects a random sampl

44、e of 100 accounts and finds that the average owed is $ with a sample standard deviation of $. If you were to conduct a test to determine whether the auditor should conclude that there is evidence that the average balance is different from $75, which test would you usea) Z-test of a population meanb)

45、 Z-test of a population proportionc) t-test of population meand) t-test of a population proportionANSWER:c十一、A manager of the credit department for an oil company would like to determine whether the average monthly balance of credit card holders is equal to $75. An auditor selects a random sample of

46、 100 accounts and finds that the average owed is $ with a sample standard deviation of $. If you wanted to test whether the average balance is different from $75 and decided to reject the null hypothesis, what conclusion could you drawe) There is not evidence that the average balance is $75.f) There

47、 is not evidence that the average balance is not $75.g) There is evidence that the average balance is $75.h) There is evidence that the average balance is not $75.ANSWER:d十二、The marketing manager for an automobile manufacturer is interested in determining the proportion of new compact-car owners who

48、 would have purchased a passenger-side inflatable air bag if it had been available for an additional cost of $300. The manager believes from previous information that the proportion is . Suppose that a survey of 200 new compact-car owners is selected and 79 indicate that they would have purchased th

49、e inflatable air bags. If you were to conduct a test to determine whether there is evidence that the proportion is different from , which test would you usei) Z-test of a population meanj) Z-test of a population proportionk) t-test of population meanl) t-test of a population proportionANSWER:b十三、A s

50、tudent claims that he can correctly identify whether a person is a business major or an agriculture major by the way the person dresses. Suppose in actuality that if someone is a business major, he can correctly identify that person as a business major 87% of the time. When a person is an agricultur

51、e major, the student will incorrectly identify that person as a business major 16% of the time. Presented with one person and asked to identify the major of this person (who is either a business or agriculture major), he considers this to be a hypothesis test with the null hypothesis being that the

52、person is a business major and the alternative that the person is an agriculture major.2. Referring to Table 9-2, what would be a Type I errora) Saying that the person is a business major when in fact the person is a business major.b) Saying that the person is a business major when in fact the perso

53、n is an agriculture major.c) Saying that the person is an agriculture major when in fact the person is a business major.d) Saying that the person is an agriculture major when in fact the person is an agriculture major.ANSWER:c3. Referring to Table 9-2, what would be a Type II errora) Saying that the

54、 person is a business major when in fact the person is a business major.b) Saying that the person is a business major when in fact the person is an agriculture major.c) Saying that the person is an agriculture major when in fact the person is a business major.d) Saying that the person is an agricult

55、ure major when in fact the person is an agriculture major.ANSWER:b4. Referring to Table 9-2, what is the “actual level of significance” of the testa)b)c)d)ANSWER:a5. Referring to Table 9-2, what is the “actual confidence coefficient”a)b)c)d)ANSWER:d6. Referring to Table 9-2, what is the value of a)b

56、)c)d)ANSWER:a7. Referring to Table 9-2, what is the value of a)b)c)d)ANSWER:b十四、Are Japanese managers more motivated than American managers A randomly selected group of each were administered the Sarnoff Survey of Attitudes Toward Life (SSATL), which measures motivation for upward mobility. The SSATL scores are summarized below.AmericanJapaneseSample Size211100Mean SSATL S