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 frame of 200 customer service times are all observed during the busiest hour of the day for this fast-food operation. The data are in the file P2_4.XLS. 

a. Use Excel to generate a simple random sample of size 10 from this frame. 

b. Compute a point estimate of the population mean from the sample selected in part a. What is the sampling error in this case? Assume that the population consists of the given 200 customer service times. 

c. Determine a good approximation to the standard error of the mean in this case. 

d. Repeat parts b and ¢ after generating a simple random sample of size 20 from the given frame.