a$.$ Set up the fraction nonconforming control chart for this process. Use the variable$-$width control limit approach. Plot the preliminary data in Table $7E\mathrm{.}2$ on the chart. Is the process in

statistical control?

b$.$ Assume that assignable causes can be found for any out$-$of$-$control points on this chart. What center line should be used for process monitoring in the next period, and how should the control

limits be calculated?