Aspen Plastics 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 (in inches) from the last six samples are

	Bottle
Sample	1	2	3	4
1	0.594	0.622	0.598	0.59
2	0.587	0.611	0.597	0.613
3	0.571	0.580	0.595	0.602
4	0.610	0.615	0.585	0.578
5	0.580	0.624	0.618	0.614
6	0.585	0.593	0.607	0.569

Assume that only these six samples are sufficient, and use the data to determine control limits for an R- and an x-chart