48. US Airways conducted a number of studies that indicated a substantial savings could be obtained by encouraging Dividend Miles frequent flyer customers to redeem miles and schedule award flights online (US Airways Attaché, February 2003). One study collected data on the amount of time required to redeem miles and schedule an award flight over the telephone. A sample showing the time in minutes required for each of 150 award flights scheduled by telephone is contained in the data set Flights. Use Minitab or Excel to help answer the following questions.

a. What is the sample mean number of minutes required to schedule an award flight by telephone?

b. What is the 95% confidence interval for the population mean time to schedule an award flight by telephone?

c. Assume a telephone ticket agent works 7.5 hours per day. How many award flights can one ticket agent be expected to handle a day?

d. Discuss why this information supported US Airways’ plans to use an online system to reduce costs.