Discuss the following:
The Golden Calendar Company has population of 16 customers. These customers are brokers who sell the calendars to stores and catalogs. The following data reflect the number of calendars sold to each of the 16 customers last year.
41,591 48,600 48,348 60,977
26,226 51,269 21,519 20,124 36,526 51,836 40,444 43,572
47,091 31,444 39,580 67,452
a. Compute the population mean and standard deviation.
b. Suppose that Golden managers selected four customers to take part in a special promotional test. The test is designed to increase the number of calendars that each customer will purchase next year. The simple random sample of four was obtained from this population. The data were:
40,444 21,519 67,452 47,091
1. Calculate the sample mean number of calendars sold.
2. How much sampling error is present in this sample?
c. A second simple random sample of 4 was obtained from the population of 16 customers. The data obtained were
36,526 51,836 20,124 43,572
1. Determine the sampling error for this sample
2. Explain why sampling error occurs and why the sampling error in part c is different than the sampling error in part b
3. Discuss the ramifications of sampling error. What problems might it cause in this case, in which the promotion is intended to increase calendar sales next year?
d. Take a sample of size n=8 from the original population.
1. Compute the sampling error
2. Compare the sampling error for this sample with those for the two samples of size n=4.
3. Without regard to the results you obtained here, explain why it is possible for a smaller sample to explain why it is possible for a smaller sample to have a smaller sampling error than a larger sample from the same population.
| Customer |
Calendars |
| 1 |
41,591 |
| 2 |
26,226 |
| 3 |
36,526 |
| 4 |
47,091 |
| 5 |
48,600 |
| 6 |
51,269 |
| 7 |
51,836 |
| 8 |
31,444 |
| 9 |
48,348 |
| 10 |
21,519 |
| 11 |
40,444 |
| 12 |
39,580 |
| 13 |
60,977 |
| 14 |
20,124 |
| 15 |
43,572 |
| 16 |
67,452 |