The upper and lower control limits are usually set at
A) the mean.
B) above the mean.
C) 3 standard deviations from the mean.
D) 2 standard deviations from the mean.

Question

Quizplus · Accepted Answer

The upper and lower control limits are commonly set at 3 standard deviations from the mean in order to capture 99.7% of the observations within the limits. This ensures that any data points outside of the control limits are considered statistically significant and can be investigated further.

The Upper and Lower Control Limits Are Usually Set at