Brian Vanecek, VP of Operations at Portland Trust Bank, Is

Multiple Choice

Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers.Accordingly, his staff recorded the waiting times for 64 randomly selected walk-in customers and determined that their mean waiting time was 15 minutes.Assume that the population standard deviation is 4 minutes.The 90% confidence interval for the population mean of waiting times is ________.

A) 14.27 to 15.73
B) 14.18 to 15.82
C) 9.88 to 20.12
D) 13.86 to 16.14
E) 18.12 to 19.87