The management of a department store is interested to estimate the difference in the amount of money spent by female and male shoppers. You are given the following information.
|
Female Shoppers |
Male Shoppers |
| Sample size |
64 |
49 |
| Sample mean |
$140 |
$125 |
| Population standard deviation |
$10 |
$8 |
A 95 percent confidence interval estimate for the difference between the average purchases of the customers using the two different credit cards is:
1. 11.68 to 18.32
2. 49 to 64
3. 8 to 10
4. 125 to 140