Which of the following statements about process quality control is NOT true?
A) Assignable cause variation is also referred as special cause variation.
B) An observation outside the control limits is an example of a special cause of variation.
C) Common cause variation can be eliminated from the process by removing the potential causes.
D) The control limits will include 99.74% of the population under the normal probability distribution assuming that the process is in control.

Question

Quizplus · Accepted Answer

A control chart assumes that 99.74% of common cause variation will fall between plus/minus 3 standard deviations of the mean, but the chart does not assign causes. It does separate special cause variation from common cause variation.

Which of the Following Statements About Process Quality Control Is