Question: The manager of a local fast-food restaurant is interested in improving the service provided to customers who use the restaurant’s drive-up window. As a first step in this process, the manager asks his assistant to record the time (in minutes) it takes to serve a large number of customers at the final window in the facility’s drive-up system. The given sample of 50 customers services times are all observed during the busiest hour of the day for this fast-food operation. -- use File2-1.Xls.

a. Based on the sample collected, construct and report a 95% confidence interval for the mean service time of all customers arriving during the busiest hour of the day at this fast-food operation.

b. Interpret the 95% confidence interval constructed in part (a).