Ten samples of 15 parts each were taken from an ongoing process to establish a p chart for control. The samples and the number of defectives in each are shown in the following table:
NUMBER OF NUMBER OF
DEFECTS IN DEFECTS IN
SAMPLE n SAMPLE SAMPLE n SAMPLE
1 15 3 6 15 2
2 15 1 7 15 0
3 15 0 8 15 3
4 15 0 9 15 1
5 15 0 10 15 0
a. Develop a p chart for 95 percent confidence (1.96 standard deviations).
b. Based on the plotted data points, what comments can you make?