The three sigma limits for a process whose distribution conforms to the normal distribution include approximately:
A) 50% of the observed values, in the long run.
B) 68% of the observed values, in the long run.
C) 95% of the observed values in the long run.
D) 99% of the observed values in the long run.

Question

Quizplus · Accepted Answer

The three sigma limits, also known as the 3-sigma rule, state that for a normal distribution, about 99.7% of the data falls within three standard deviations (σ) of the mean. Therefore, approximately 99% of the observed values are included within these limits in the long run.

The Three Sigma Limits for a Process Whose Distribution Conforms