The control limits for an x-bar chart are how many standard deviations above and below the process mean?
A) one
B) two
C) three
D) four

Question

Quizplus · Accepted Answer

The control limits for an x-bar chart are typically set at three standard deviations above and below the process mean. This is based on the principle that for a normally distributed process, about 99.73% of all samples should fall within these limits if the process is in control.

The Control Limits for an X-Bar Chart Are How Many