Assignment:
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.
1. What are the control limits for the R chart?
2. What are the control limits for the x-bar Chart?
3. Is the process in control?