Managing for Quality and Performance Excellence 9th Edition by James Evans,William Lindsay

Exercise 33

The distribution center manager at Internet distributor CyberAuto Warehouse wants to find a confidence interval for the average time required for an associate to fill an order for shipment. A sample of 16 orders is taken and the mean time was found to be 8.5 minutes, with a standard deviation of 2.8 minutes. Compute 95 percent and 99 percent confidence intervals. Which one is larger? Explain why.