A quality control chart is used to monitor the customer wait time at a local call center. Sample means of five times are averaged and plotted over time. Over the last hundred sample means, one sample mean was outside a control limit. The chart shows:
A) chance variation.
B) standard variation.
C) assignable variation.
D) total variation.

Question

Quizplus · Accepted Answer

The chart shows chance variation because one sample mean out of the last hundred was outside a control limit. This is within the expected range of random variation.

A Quality Control Chart Is Used to Monitor the Customer