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 an assistant to record the time (in seconds) it takes to serve a large number of customers at the final window in the facility’s drive-up system. The file P08_07.xlsx contains a random sample of 200 service times during the busiest hour of the day.
a. Identify the relevant population.
b. Construct and interpret 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.
c. If the manager wants to improve service, at least during the busiest time of day, does this confidence interval provide useful information? What useful information does it not provide?