One way that a control chart could be utilized for healthcare coding and billing would be to count the number of bills that are flagged by audit as being coded incorrectly. You could count the number of bills on a monthly basis that are flagged incorrectly, and given that the sample size (total number of bills audited each month) would vary, use the NP chart to determine the proportion of non-conforming bills month over month. Discuss briefly what other healthcare coding and billing attributes would you want to look at using attribute control charts? Why?