Discuss the below:
Q) Arthur D. Little, Inc. estimates that approximately 70% of mail received by a household is advertisements (Time, July 14, 1997). A sample of 20 households shows the following data for the number of advertisements received and the total number of pieces of mail received during one week.
a) What is the point estimate of the population mean number of advertisements received per week? What is the 95% confidence interval for the population mean?
b) What is the point estimate of the population mean number of pieces of mail received per week? What is the 95% confidence interval for the population mean?
c) Use the point estimates in parts (a) and (b). Do these estimates agree with the statement that approximately 70% of mailings are advertisements?
| Household |
Advertisements |
Total Mail |
| 1 |
24 |
35 |
| 2 |
9 |
14 |
| 3 |
18 |
30 |
| 4 |
9 |
12 |
| 5 |
15 |
28 |
| 6 |
23 |
33 |
| 7 |
13 |
20 |
| 8 |
17 |
20 |
| 9 |
20 |
23 |
| 10 |
20 |
25 |
| 11 |
13 |
19 |
| 12 |
16 |
28 |
| 13 |
20 |
27 |
| 14 |
17 |
22 |
| 15 |
21 |
24 |
| 16 |
21 |
33 |
| 17 |
15 |
25 |
| 18 |
15 |
24 |
| 19 |
18 |
24 |
| 20 |
12 |
16 |