The value for "z" used in quality control charts is based on the degree of confidence you want to have in the resulting UCL and LCL values.

Question

Quizplus · Accepted Answer

This is true. The z-value, also known as the standard deviation multiplier, is based on the level of confidence desired for the control chart limits. Higher levels of confidence will result in wider control limits, while lower levels of confidence will result in tighter control limits.

The Value for "Z" Used in Quality Control Charts Is