The manager of the accounting office of a large hospital has the business objective of reducing the number of incorrect numbers entered into the computer system. A subgroup of 200 account numbers is selected from each day’s output, and each account number is inspected to determine whether it is a nonconforming item. The results for a period of 39 days are stored in Errorspc.
a. Construct a p chart for the proportion of nonconforming items. Does the process give an out of control signal?
b. Based on your answer in (a), if you were the manager of the accounting office, what would you do to improve the process of account number entry?