Discuss the below:
Q: Johnson Company produces plastic bottles to customer order. The quality inspector randomly selects four bottles from the bottle machine and measures the outside diameter of the bottle neck, a critical quality dimension that determines whether the bottle cap will fit properly. The dimensions (inch) from the last six samples are provided below. What are the control limits for the R chart? What are the control limits for the x-bar Chart? Is the process in control?
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|
Hoak
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|
Sample
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1
|
2
|
3
|
4
|
|
1
|
0.602
|
0.613
|
0.574
|
0.601
|
|
2
|
0.5%
|
0.602
|
0.607
|
0.606
|
|
3
|
0.582
|
0.551
|
0.584
|
0.598
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|
4
|
0.631
|
0.604
|
0.596
|
0.576
|
|
5
|
0.597
|
0.623
|
0.609
|
0.603
|
|
6
|
0.584
|
0.579
|
0.621
|
0.578
|