Joe studied his control chart and noticed it had been built with repeated samples of ten units and three sigma limits that were UCL = 109.0125 and LCL = 90.9875.What is the process standard deviation?
A)9.5
B)6.7
C)5.2
D)3

Question

Quizplus · Accepted Answer

The process standard deviation is calculated as (UCL - LCL) / (6 * sigma), where sigma is the number of standard deviations used to calculate the control limits. In this case, sigma = 3, so the process standard deviation is (109.0125 - 90.9875) / (6 * 3) = 9.5.

Joe Studied His Control Chart and Noticed It Had Been