A set of data obtained from inspection of castings, with a sample size of 20 castings are shown in the table:–
|
Group
No.
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
|
No. of
defects
|
76
|
68
|
76
|
89
|
47
|
69
|
83
|
93
|
70
|
79
|
Compute
- The process average and control limits.
- The process average for future production and revised control limits.