The UCL and LCL for an $ \bar{x} $ chart are 25 and 15 respectively. The central line is 20, and the process variability is considered to be in statistical control. The results of the next six sample means are 18, 23, 17, 21, 24, and 16. What should you do?
A) Nothing; the process is in control.
B) Explore the assignable causes because the second, fourth, and fifth samples are above the mean.
C) Explore the assignable causes because there is a run.
D) Explore the assignable causes because there is a trend.

Question

Quizplus · Accepted Answer

The sample means all fall within the control limits (UCL = 25, LCL = 15), indicating the process is in control. There's no evidence of a specific pattern (like a trend or run) that would suggest the process is out of control.

The UCL and LCL for An xˉ \bar{x} xˉ Chart Are 25 and 15 Respectively

The UCL and LCL for An $\bar{x}$ Chart Are 25 and 15 Respectively