1. The results of an inspection of DNA samples taken over the past 10 days are given below. Sample size is 100.
|
Day
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
|
Defectives
|
7
|
6
|
6
|
9
|
5
|
6
|
0
|
8
|
9
|
1
|
a) Construct a 3-sigma p -chart using this information.
b) Using the control chart in part (a), and finding that the number of defectives on the next three days are 12, 5, and 13, is the process in control?
2. In the past, the defective rate for your product has been 1.5%. What are the upper and lower control chart limits if you wish to use a sample size of 500 and z = 3?