Discussion:
Q: The management of a department store is interested in estimating the difference between the mean credit purchases of customers using the store's credit card versus those customers using a national major credit card. You are given the following information.
Store's Card Major Credit Card
Sample size 64 49
Sample mean $140 $125
Population standard deviation $10 $8
a)A point estimate for the difference between the mean purchases of the users of the two credit cards is
b) At 95% confidence, the margin of error is
c) A 95% confidence interval estimate for the difference between the average purchases of the customers using the two different credit cards is