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

Question

Quizplus · Accepted Answer

The upper and lower control limits are usually set at three standard deviations from the mean. This is because in a normal distribution, approximately 99.7% of the data falls within three standard deviations of the mean, making it a good range for detecting unusual data points or outliers.

The Upper and Lower Control Limits Are Usually Set ________