Koufos Imports wants to estimate the average value of its current accounts receivable. In all, there are 2000 accounts. A simple random sample of 40 accounts is selected. The average amount due the firm in the sample is $6500. The sample standard deviation is $1600.
a. Show the 95% confidence interval estimate of average accounts receivable.
b. Show the 95% confidence interval estimate of the total amount owed the firm by these 2000 accounts.