Chapter 19.2, Problem 5E

Temperature is used to measure the output of a production process. When the process is in control, the mean of the process is μ = 128.5 and the standard deviation is σ = .4.

1. a. Construct the $\bar{x}$ chart for this process if samples of size 6 are to be used.
2. b. Is the process in control for a sample providing the following data?

128.8

128.2

129.1

128.7

128.4

129.2

1. c. Is the process in control for a sample providing the following data?

129.3

128.7

128.6

129.2

129.5

129.0