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.

a.Construct the x¯ chart for this process if samples of size 6 are to be used.

b.In the process in control for a sample providing the following data?

128.8 128.2 129.1 128.7 128.4 129.2

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

129.3 128.7 128.6 129.2 129.5 129.0