Problem: The manager of an assembly line took 5 samples each with 6 observation under ideal conditions to develop control limits for an X bar chart The mean and range of each sample is shown in the table below:
What would be the 3 standard deviation lower control limit?
| Number |
Mean |
Range |
| 1 |
2.18 |
0.33 |
| 2 |
2.12 |
0.38 |
| 3 |
1.86 |
0.4 |
| 4 |
1.98 |
0.38 |
| 5 |
2.02 |
0.35 |