At a local bank, a sample of 150 calls from a customer service line was taken and found that callers were kept waiting on average 8 minutes. The sample standard deviation is 3 minutes. Do not use Minitab and show all of your calculations.

1. Calculate a 95% confidence interval for the true population mean wait time for callers.

1. Interpret for management the 95% confidence interval.

1. How can a manager at this company use this information? Be specific.