To draw the p-chart for the nonconforming units.
The coating of the candy bar is currently made by a process that can result in surface cracking. To monitor the process, it was decided to construct a P chart. During four shifts, 30 samples of size 60 were collected, and the results are as follows:
|
Sample Number
|
Nonconforming units found
|
Sample Number
|
Nonconforming units found
|
|
1
|
2
|
16
|
3
|
|
2
|
6
|
17
|
4
|
|
3
|
1
|
18
|
6
|
|
4
|
3
|
19
|
4
|
|
5
|
7
|
20
|
3
|
|
6
|
9
|
21
|
1
|
|
7
|
2
|
22
|
4
|
|
8
|
1
|
23
|
3
|
|
9
|
7
|
24
|
6
|
|
10
|
2
|
25
|
2
|
|
11
|
0
|
26
|
3
|
|
12
|
3
|
27
|
4
|
|
13
|
1
|
28
|
3
|
|
14
|
4
|
29
|
6
|
|
15
|
6
|
30
|
2
|
a. Set up the trial control limits for a 3-sigma P chart and plot the data.
b. Comment as to the stability of the process.