A nationwide parcel delivery service keeps track of the number of late deliveries (more than 30 minutes past the time promised to clients) per day. They plan on using a control chart to plot their results. Which type of control chart(s) would you recommend?

Question

Quizplus · Accepted Answer

C-charts are used for monitoring the number of defects per unit when the number of opportunities for a defect is constant. In this case, the "unit" is a day, and the "defects" are the late deliveries. This makes the c-chart the appropriate choice for tracking the number of late deliveries per day.

A Nationwide Parcel Delivery Service Keeps Track of the Number xˉ\bar xxˉ

A Nationwide Parcel Delivery Service Keeps Track of the Number $\bar x$