商务统计学笔试复习题

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)

2、all 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 ov

3、er 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 sample?a) Telephone directory.b) Voting registry.c) The list of customers who returned the registration card.d) A list o

4、f 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 variable.d)

5、 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 random variable.d) pa

6、rameter.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 numerical random variable.c) catego

7、rical 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.c) categorical random variable.d) paramet

8、er.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. the possible responses to the question How would you

9、 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 variable.d) parameter.ANSWER: c9. the possible responses to the questio

10、n 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 responses to the question Out of a 100 point score with 100 being the highest a

11、nd 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 random variable.d) parameter.ANSWER:a11. the possible responses to the question In wh

12、ich 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 university was concerned about alcohol abuse on her campus and wanted to find out the proportion of s

13、tudents 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 campus bars on the weekend before the final exam week is an example of e) a categorical random varia

14、ble.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 the proportion of students at her university who visited campus bars on the weekend before the fina

15、l 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 students at her university who visited campus bars on the weekend before the final exam week is an examp

16、le 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 her campus and wanted to find out the proportion of students at her university who visited campus b

17、ars 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 is an example of _.m) a categorical random variable.n) a discrete random variable.o) a parameter.

18、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 212323252627272829291. Referring to Table 2-11, if a frequency distribution for the defects data is con

19、structed, 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 defects data is constructed, using 0 but less than 5 as the first class, the relative frequency of the “15 but les

20、s than 20” class would be _.ANSWER:0.08 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 first 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 th

21、an 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 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 t

22、han 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 distribution uses 0 but less than 5 as the first class.ANSWER:Defects CumPct005161040154820562572301006. Referring to Table 2-11, construct a

23、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 percentage 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

24、 much attention in both academic and political arenas. A sociologist recently conducted a survey of citizens over 60 years 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:60616263646566686869707

25、3737475767681818286878990921. Referring to Table 3-1, calculate the arithmetic mean age of the uninsured senior citizens to the nearest hundredth of a year.ANSWER:74.04 years2. Referring to Table 3-1, identify the median age of the uninsured senior citizens.ANSWER:73 years3. Referring to Table 3-1,

26、identify the first quartile of the ages of the uninsured senior citizens.ANSWER:65.5 years4. Referring to Table 3-1, identify the third quartile of the ages of the uninsured senior citizens.ANSWER:81.5 years5. Referring to Table 3-1, identify the interquartile range of the ages of the uninsured seni

27、or citizens.ANSWER:16 years6. Referring to Table 3-1, identify which of the following is the correct statement.a) One fourth of the senior citizens sampled are below 65.5 years of age.b) The middle 50% of the senior citizens sampled are between 65.5 and 73.0 years of age.c) The average age of senior

28、 citizens sampled is 73.5 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 statement.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 65.5

29、and 73.0 years of age.c) 25% of the senior citizens sampled are older than 81.5 years of age.d) All of the above are correct.ANSWER:c8. Referring to Table 3-1, what type of shape does the distribution of the sample appear to have?ANSWER:Slightly positive or right-skewed.9. Referring to Table 3-1, ca

30、lculate the variance of the ages of the uninsured senior citizens correct to the nearest hundredth of a year squared.ANSWER:94.96 years210. Referring to Table 3-1, calculate the standard deviation of the ages of the uninsured senior citizens correct to the nearest hundredth of a year.ANSWER:9.74 yea

31、rs11. Referring to Table 3-1, calculate the coefficient of variation of the ages of the uninsured senior citizens.ANSWER:13.16%七、The stem-and-leaf display below represents the number of cargo manifests approved by customs inspectors of the Port of New York in a sample of 35 days. STEMLEAVES1H678892L

32、00111222233334442H55666788993L1122Note (1):1H means the “high teens” 15, 16, 17, 18, or 19; 2L means the “low twenties” 20, 21, 22, 23, or 24; 2H means the “high twenties” 25, 26, 27, 28, or 29, etc. Note (2):For this sample, the sum of the observations is 838, the sum of the squares of the observat

33、ions is 20,684, and the sum of the squared differences between each observation and the mean is 619.89. 1. Referring to Table 3-4, the arithmetic mean of the customs data is _.ANSWER:23.92. Referring to Table 3-4, the median of the customs data is _.ANSWER:233. Referring to Table 3-4, the first quar

34、tile 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, the interquartile range of the customs data is _.ANSWER:67. Referring to Table 3-4,

35、 the variance of the customs data is _.ANSWER:18.28. Referring to Table 3-4, the standard deviation of the customs data is _.ANSWER:4.39. Referring to Table 3-4, the coefficient of variation of the customs data is _ percent.ANSWER:17.8% or 18%10. Referring to Table 3-4, the five-number summary for t

36、he 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 normal distribution with standard deviation 8 hours. A random sample of 4

37、 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 hours?ANSWER:0.30852. what is the probability that the sample mean is more than 3 hours below the population mean

38、?ANSWER:0.22663. what is the probability that the sample mean differs from the population mean by less than 2 hours?ANSWER:0.3829 using Excel or 0.3830 using Table E.24. what is the probability that the sample mean differs from the population mean by more than 3 hours?ANSWER:0.4533 using Excel or 0.

39、4532 using Table E.2九、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 0.15 feet. A sample of 70 cut sheets yields a me

40、an length of 12.14 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:2.582. Referring to Table 8-3, the confidence interval goes from _ to _.ANSWE

41、R:12.09 to 12.193. 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

42、sample 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

43、estimate the mean length to within 0.03 with 99% confidence. Then the sample size would be _.ANSWER:165.8724 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

44、a random sample of 100 accounts and finds that the average owed is $83.40 with a sample standard deviation of $23.65. 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 use?a) Z-te

45、st of a population meanb) 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 s

46、elects a random sample of 100 accounts and finds that the average owed is $83.40 with a sample standard deviation of $23.65. If you wanted to test whether the average balance is different from $75 and decided to reject the null hypothesis, what conclusion could you draw?e) There is not evidence that

47、 the average balance is $75.f) There 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 prop

48、ortion of new compact-car owners who 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 0.30. Suppose that a survey of 200 new compact-car owners is selected and 79 in

49、dicate that they would have purchased the inflatable air bags. If you were to conduct a test to determine whether there is evidence that the proportion is different from 0.30, which test would you use?i) Z-test of a population meanj) Z-test of a population proportionk) t-test of population meanl) t-

50、test of a population proportionANSWER:b十三、A student 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

51、% of the time. When a person is an agriculture 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

52、test with the null hypothesis being that the 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 error?a) Saying that the person is a business major when in fact the person is a business major.b) Saying that the per

53、son 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 agriculture major when in fact the person is an agriculture major.ANSWER:c3. Referring to Table 9-2, w

54、hat would be a Type II error?a) 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 person is an agriculture major.c) Saying that the person is an agriculture major when in fact the person is a business

55、 major.d) Saying that the person is an agriculture 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 test?a) 0.13b) 0.16c) 0.84d) 0.87ANSWER:a5. Referring to Table 9-2, what is the “actual confidence coefficient”?a) 0.13b) 0.16c) 0.84d) 0.87ANSWER:d6. Referring to Table 9-2, what is the value of ?a) 0.13b) 0.16c) 0.84d) 0.87ANSWER:a7. Referring to Table 9-2, what is the value of ? a) 0.13b) 0.16c) 0.84d) 0.87ANSWER:b十四、Are Japanese managers more motiv