A process considered to be in control measures an ingredient in ounces. A quality inspector took 10 samples, each with 5 observations as follows:

Samples	Observations
	1	2	3	4	5
1	10	9	10	9	12
2	9	9	11	11	10
3	13	9	10	10	9
4	10	10	11	10	10
5	12	10	9	11	10
6	10	10	8	12	9
7	10	11	10	8	9
8	13	10	8	10	8
9	8	8	12	12	9
10	10	12	9	8	12

1. Using this information, obtain three-sigma (i.e., z=3) control limits for a mean control chart and control limits for a range chart, respectively. It is known from previous experience that the standard deviation of the process is 1.36.

(25 marks)

2. Discuss whether the process is in control or not.

(5 marks)