The manager of a local fastfood restaurant is interested in improving the service provided to customers who use the restaurant's driveup window. As a first step in this process, the manager asks his assistant to record the time it takes to serve a large number of customers at the nal Window in the facility's driveup system. The results are in the file PO7_08.x|sx, which consists of nearly 1200 service times. For this problem, you can assume that the population is the data in this file. Use Excel to generate a simple random sample of size 30 from the data. Round your answers to two decimal places, if necessary. a. Calculate a point estimate of the population mean from the sample selected above. 58.35 6 What is the sampling error, that is, by how much does the sample mean differ from the population mean? 2.85 (:0 b. Calculate a good approximation for the standard error of the mean. 4.53 M c. [f you wanted to halve the standard error from part c, what approximate sample size would you need? 120 9 Why is this only approximate? Because the exact standard error is determined by the M standard deviation, not the population v (:0 standard deviation