Nine samples of 20 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: Sample - n - Number of defectives in the sample
1 20 0
2 20 2
3 20 4
4 20 0
5 20 0
6 20 2
7 20 0
8 20 5
9 20 1
a) Develop a p-chart for 96% confidence.
b) Based on the plotted data points, what comments can you make?