Question: A company randomly selects 50 shipping records every day to determine the number of orders that are shipped late. The following are the most recent 20 days of samples. The company wants to use the sampled data to develop a p chart to monitor the proportion of late shipments. Using the data below, develop a p chart to monitor this process. Does the process appear to be in control?
|
Sample
|
n = Sample Size
|
Number of Late Shipments
|
Number defective (p)
|
|
1
|
50
|
3
|
0.06
|
|
2
|
50
|
5
|
0.1
|
|
3
|
50
|
2
|
0.04
|
|
4
|
50
|
4
|
0.08
|
|
5
|
50
|
6
|
0.12
|
|
6
|
50
|
4
|
0.08
|
|
7
|
50
|
4
|
0.08
|
|
8
|
50
|
2
|
0.04
|
|
9
|
50
|
4
|
0.08
|
|
10
|
50
|
5
|
0.1
|
|
11
|
50
|
2
|
0.04
|
|
12
|
50
|
3
|
0.06
|
|
13
|
50
|
5
|
0.1
|
|
14
|
50
|
3
|
0.06
|
|
15
|
50
|
6
|
0.12
|
|
16
|
50
|
4
|
0.08
|
|
17
|
50
|
5
|
0.1
|
|
18
|
50
|
4
|
0.08
|
|
19
|
50
|
5
|
0.1
|
|
20
|
50
|
2
|
0.04
|