Golden Gopher Airline issues thousands of aircraft boarding passes to passengers each day. In some cases a boarding pass is spoiled for various reasons and discarded by the airline agent before the final boarding pass is issued to a customer. To control the process for issuing boarding passes, the airline has sampled the process for 100 days and determined the average proportion of defective passes is .006 (6 in every 1000 passes are spoiled and discarded). In the future, the airline plans to take a sample of 500 passes that are issued each day and calculate the proportion of spoiled passes in that sample for control chart purposes.

a. What is the sample size (n) for this problem? Explain the significance of the 100 days used to determine the average proportion defective.

b. Calculate the center line and the upper and lower control limits, using three standard deviations for control purposes.