A quality control engineer has collected 5 samples, each of size 30. The numbers of defective items in the samples are given in the table below.
|
Sample Number
|
I
|
II
|
III
|
IV
|
V
|
|
Number of defective items
|
3
|
2
|
4
|
1
|
5
|
The upper three-sigma (3$\sigma$) control limit for the proportion of defective items in any sample is ____________