A marketing research analyst collects data for a random sample of 100 customers out of the 4,000 who purchased a particular “coupon special.” The 100 people spent an average of X = $24:57 in the store...

A marketing research analyst collects data for a random sample of 100 customers out of the 4,000 who purchased a particular “coupon special.” The 100 people spent an average of X = $24:57 in the store with a standard deviation of s = $6:60. Using a 95 percent confidence interval, estimate (a) the mean purchase amount for all 4,000 customers and (b) the total dollar amount of purchases by the 4,000 customers.