If ?σ is the population standard deviation, k the number of samples or subgroups, and n the sample size (number of observations in each subgroup), what is the distance from the centre line to the upper control limit?
A) σ
B) 3 σ
C) 3 σ / √k
D) 3 σ / √n

Question

Quizplus · Accepted Answer

The distance from the center line to the upper control limit in a control chart is typically 3 standard deviations of the sample mean, which is calculated as 3σ/√n, where n is the sample size.

If ?σ Is the Population Standard Deviation, K the Number