Chapter 13.4, Problem 13.11LM

The data in the following table were collected for the purpose of constructing an x-chart.

1. a. Calculate $\bar{x}$ and R for each sample.
2. b. Calculate $\overline{\stackrel{¯}{x}}$ and $\bar{R}$.
3. c. Calculate and plot the centerline and the upper and lower control limits for the $\bar{x}$ -chart.
4. d. Calculate and plot the A, B, and C zone boundaries of the $\bar{x}$ -chart.
5. e. e Plot the 20 sample means on the $\bar{x}$ -chart Is the process in control? Justify your answer