Discussion:
Q: You are the manager of a restaurant for a fast food franchise. Last month, the mean waiting time at the drive-through window, as measured from the time a customer places an order until the time the customer receives the order, was 3.7 minutes. The franchise helped you institute a new process intended to reduce waiting time. You select a random sample of 64 orders. The sample mean waiting time is 3.57 minutes with a sample standard deviation of 0.8 minute. At the 0.5 level of significance, is there evidence that the population mean waiting time is now less than 3.7 minutes?