An x-bar control chart was examined and no data points fell outside of the limits. Can this process be considered in control?
A) No, there could be a pattern to the points.
B) No, the R-chart must be checked.
C) No, the number of samples must be known.
D) Yes
E) Both A and B

Question

Quizplus · Accepted Answer

An x-bar control chart not having any data points outside the limits does not guarantee the process is in control. Patterns within the control limits, such as cycles or trends, can indicate a lack of control. Additionally, the R-chart, which monitors the process variability, must also be in control for the process to be considered in control.

An X-Bar Control Chart Was Examined and No Data Points