Larry's boat shop wants to monitor the number of blemishes in the paint of each boat. Construct a 3-sigma c-chart to determine if their paint process is in control using the following data

Sample Number Number of
Defects
1 3
2 4
3 2
4 1
5 3
6 2
7 1
8 4
9 2
10 3

Total units sampled 10
Total defects 25
Defect rate, c-bar 2.5
Standard deviation 1.581
z value 3

Upper Control Limit 7.243
Center Line 2.5
Lower Control Limit 0

The process is in control.