6. Your supervisor, Lisa Lehmann has asked you to report on the output of a machine on the factory floor. The machine is supposed to be producing optical lenses with a mean of 50 grams and a range of 3.5 grams. The following Table contains the data for a sample size of 10 taken during the past three hours:

Sample Number	Sample Average	Sample Range
1	55	3
2	47	1
3	49	5
4	50	3
5	52	2
6	57	6
7	55	3
8	48	2
9	51	2
10	56	3

Develop the appropriate control chart limits for the machine. What seems to be happening? Explain.