Reference no: EM132852755

A manager of a large grocery store wants to increase the customer service satisfaction rate. He is thinking about giving a 5% discount to customers who wait in line for more than 8 minutes. However, to get a better idea about the current waiting times, she hired a student to measure the time spent by customers waiting in line. Using a stopwatch, the student determined the amount of time between the time a customer joined the line and the time he or she reached the teller. A total of 50 customers' times were recorded. The mean was 5.79 minutes with a standard deviation of 2.86 minutes.

Question #1: The store manager would like to determine whether there is enough evidence suggesting that the mean waiting time for the grocery store's customers is less than 6 minutes. Conduct the corresponding hypothesis test using a 10% significance level and the p-level approach.

Question #2: Construct the appropriate one-sided 90% confidence interval for the true mean waiting time for the grocery store's customers. Is this interval consistent with your conclusion in Question #1? Explain.

Question #3: How large a sample should it be to estimate the mean waiting time for the grocery store's customers with a margin of error of 0.34 and a 90% confidence? Assume that the waiting time standard deviation is 2.86 minutes.