The natural tolerance limits for a normally distributed process that is in statistical control:
A)Extend beyond the specification limits when a process is capable
B)Are within the specification limits when a process is capable
C)Contain approximately 99.73 percent of the individual process measurements
D)Both B and C are correct
E)Both A and C are correct

Question

Quizplus · Accepted Answer

The natural tolerance limits for a normally distributed process that is in statistical control contain approximately 99.73 percent of the individual process measurements, according to the three-sigma rule. When a process is capable, the tolerances are within the specification limits. Therefore, both options B and C are correct. Option A is not true since the specification limits are the boundaries provided by the customer, and if the natural tolerance limits are beyond the specification limits, then the process is not considered capable.

The Natural Tolerance Limits for a Normally Distributed Process That