When the purpose of sampling is to detect when a process becomes too variable,the chart of choice will be a c-chart.

Question

Quizplus · Accepted Answer

The correct chart for detecting when a process becomes too variable, in terms of the dispersion or variability of the process, is the R-chart (range chart) or S-chart (standard deviation chart), not the c-chart. The c-chart is used for monitoring the number of defects per unit in processes where the opportunity for defects is constant.

When the Purpose of Sampling Is to Detect When a Process