To construct a p-chart for a manufacturing process, 25 samples of size 200 were drawn from the process. The number of defectives in each sample is listed in time order in the table that follows. Defectives 16 14 9 11 15 8 12 16 17 13 15 10 9 12 14 11 8 7 12 15 9 16 13 11 10

a. Calculate the proportion defective in each sample.

b. Calculate and plot pQ and the upper and lower control limits for the p-chart.

c. Calculate and plot the A, B, and C zone boundaries on the p-chart.

d. Plot the sample proportions on the p-chart and connect them with straight lines.

e. Use pattern-analysis Rules 1–4 for detecting the presence of special causes of variation (Figure 13.22) to determine whether the process is out of control.