An inspector counted the number of defective monthly billing statements of a company telephone in each of 20 samples. Using the following information, construct a control char that will describe 99.74 percent of the chance variation in the process when the process is in control. Each sample contained 100 statements.
|
Sample
|
Number of Defectives
|
Sample
|
Number of Defectives
|
Samples
|
Number of Defectives
|
Samples
|
Number of Defectives
|
|
1
|
4
|
6
|
11
|
11
|
8
|
16
|
10
|
|
2
|
10
|
7
|
10
|
12
|
12
|
17
|
8
|
|
3
|
12
|
8
|
22
|
13
|
9
|
18
|
12
|
|
4
|
3
|
9
|
13
|
14
|
10
|
19
|
10
|
|
5
|
9
|
10
|
10
|
15
|
21
|
20
|
16
|
Total Defectives: 220