Use the following information to answer questions 1. , 2. and 3.
The following data represent the retail price (in dollars) of a sample of 16 different brands of video cassette recorder
899 1199 899 1050 725 1195 830 1595
1050 1285 750 795 1040 629 899 1160
1. The mean and standard deviation retail price for the sample of 16 video cassette recorders are:
A. $1000 and $240.10 respectively.
B. $1000 and $247.97 respectively.
C. $1000 and $15.75 respectively.
D. $1000 and $15.50 respectively.
E. $974.50 and $247.97 respectively.
2. The mode and median retail price for the sample of 16 video cassette recorders are:
A. $1050 and $969.50 respectively.
B. $899 and $969.50 respectively.
C. $899 and $899 respectively.
D. $899 and $1040 respectively.
E. $1050 and $1040 respectively.
3. The coefficient of variation is
A. 4.03
B. 4.16
C. 0.24
D. 0.25
E. 0.02
4. The lifetimes of a sample of 40, 100-watt light globes were organised into the following frequency distribution using Excel.
The Excel histogram which most correctly represents this data is given by
5. Given that P(A) = 0.2 and P(B) = 0.3 and that A and B are independent events, then P(A|B) is
A. 0.2
B. 0.6
C. 0
D. 0.06
E. unable to be determined from the information provided.
6. Information was obtained from students as they left the University Coop bookshop during the first week of classes. Which of the following variables would be classified as ratio data.
A. The course being studied.
B. The type of computer owned by the student
C. The amount of money spent on books.
D. The method of payment.
E. The students progress through the course ie 1st year, 2nd year, etc.
7. Which of the following measures of spread (dispersion) is least affected by the presence of extreme (outlying) values?
A. Variance
B. Range
C. Median
D. Interquartile range
E. Standard deviation
8. A management analyst has been asked to investigate an office computing system in an attempt to discover a malfunction affecting the network communications system. The network consists of six computers, two of which have defective operating systems. Suppose the analyst randomly selects three of the computers for analysis during the first week, of this activity, what is the probability that both of the defective computers are discovered in the first week?
A. 1/9
B. 1/15
C. 1/5
D. 1/3
E. 4/9
Use the following information to answer questions 9. and 10.
A sample of 500 respondents was selected in a large metropolitan area in order to determine various information concerning consumer behaviour. Among the questions asked was ‘Do you enjoy shopping for clothing?" Of the 240 males surveyed, 136 answered yes, while 224 of the females answered yes.
9. What is the probability that a randomly selected respondent enjoys shopping for clothing?
A. 0.448
B. 0.720
C. 0.272
D. 0.622
E. 0.378
10. Suppose the respondent chosen is female. What is the probability that she does not enjoy shopping for clothing?
A. 0.138
B. 0.257
C. 0.450
D. 0.433
E. 0.072
11. Maintenance records suggest that only 1 out of every 100 electric razors of a certain brand requires repair during the first year of use. A retail store has just purchased 10 razors of this brand. Find the probability that 2 of the razors require repair during the first year of use.
A. 0.004
B. 1.000
C. 0.0001
D. 0.02
E. 0.996
Use the following information to answer questions 12. and 13.
The safety director for a manufacturing company reports that industrial accidents requiring medical treatment occur randomly and independently at the rate of 3.5 accidents per month.
12. Find the probability that there are more than 5 accidents in a given month.
A. 0.133
B. 0.142
C. 0.858
D. 0.935
E. 0.065
13. Find the probability that there are between 6 and 12 accidents in the next two months.
A. 0.523
B. 0.348
C. 0.374
D. 0.142
E. 0.497
14. Given Z is the standard normal random variable, then P(Z < -1.05) is
A. 0.3531
B. 0.5531
C. 0.6469
D. 0.1469
E. 0.0668
15. X is a normally distributed random variable with a mean of 10 and a standard deviation of 5. If P(X > a) = 0.1 then
A. a = 16.4
B. a = 11.25
C. a = 1.28
D. a = 0.25
E. a = 3.6
16. The amount of time a person is required to wait for an elevator in a large department store is uniformly distributed with a range of waiting time from no wait (0 seconds) to 3 minutes and 30 seconds wait. A recent study in consumer behaviour suggests that if customers are required to wait more than two minutes and 45 seconds, they develop negative impressions of the commitment of the store to customer service. Based on this study, what proportion of customers using the department store's elevator are likely to develop negative impressions of the store's commitment to customer service?
A. 31.25%
B. 68.75%
C. 21.43%
D. 25.76%
E. 78.57%
17. A retail variety store that advertises extensively by mail circulars expects a sale from 1 out of every 20 mailings. Suppose 100 prospects are randomly selected from a city wide mailing. What is the probability that at least 10 sales will result from the 100 mailings?
A. 0.0059
B. 0.4808
C. 0.0110
D. 0.4890
E. 0.0192
18. Long distance telephone calls are normally distributed with a mean of 8 minutes and a standard deviation of 2 minutes. If random samples of 25 calls were selected the proportion of mean call times between 7.5 and 8.2 minutes would be
A. 0.9938
B. 0.2029
C. 0.0589
D. 0.5859
E. 0.1385
19. The following multiple boxplot, created in Excel, shows the price per litre for a sample of 30 brands of interior paint and a sample of 26 brands of exterior paint.
The statement which best describes the relationship between the price of the different brands of interior and exterior paints is:
A. The interior and exterior paint prices are both approximately normally distributed.
B. The interior paint prices are approximately normally distributed while the exterior paint prices are negatively skewed.
C. The interior and exterior paint prices are both positively skewed.
D. The interior and exterior paint prices are both negatively skewed.
E. The interior paint prices are approximately normally distributed while the exterior paint prices are positively skewed.
20. A sample of 20 observations is taken from a population which has 200 elements. The sampling distribution of is :
A. approximately normal because it is always approximately normally distributed.
B. approximately normal because the sample size large in comparison to the population size.
C. approximately normal because of the central limit theorem.
D. normal if the population is normally distributed.
E. approximately normal because the sample size is small in comparison to the population size.