Use the control chart limits developed in given Exercise and the following sample results to evaluate whether the process is in control:
|
Sample
|
|
|
1
|
2
|
3
|
4
|
5
|
6
|
|
Mean burst strength
|
3390
|
3447
|
3410
|
3466
|
3440
|
3384
|
Exercise
When the robot welder is functioning properly, the natural gas cylinders being produced have an average burst strength of 3400 psi, with a standard deviation of 100 psi.
Determine the centerline and the upper and lower control limits for a 3-sigma mean control chart in which each sample consists of 4 cylinders.