Question

1) A process that is assumed to be in control with limits of 89 ± 2 had sample averages for the x-bar chart of the following: 87.1, 87, 87.2, 89, 90, 88.5, 89.5, and 88. Is the process in control? A) Yes. B) No, one or more averages exceeded the limits. C) Not enough information to tell. D) No, there is a distinguishable trend. E) No, two or more consecutive points are very near the lower (or upper) limit.

Answer 1

E) No, two or more consecutive points are very near the lower (or upper) limit.

Explanation:

A process that is assumed to be in control with limits of 89 ± 2 with following sample averages:

87.1, 87, 87.2, 89, 90, 88.5, 89.5, and 88

We can see that the process is not in control and there are two or more consecutive points that are very near the lower (or upper) limit.

Hence, option E is correct.