The BelSante Company operates retail pharmacies in 10 eastern states. Recently, the company’s internal audit department selected a random sample of 300 prescriptions issued throughout the system. The objective of the sampling was to estimate the average dollar value of all prescriptions issued by the company. The following data were collected:
= $14.23
s = 3.00
a. Determine the 90% confidence interval estimate for the true average sales value for prescriptions issued by the company. Interpret the interval estimate.
b. One of its retail outlets recently reported that it had monthly revenue of $7,392 from 528 prescriptions. Are such results to be expected? Do you believe that the retail outlet should be audited? Support your answer with calculations and logic.