Question

Nancy, Inc. manufactures 4 ounce chocolate bars. Random samples of size four were taken and weighed. Nine hours of observation provided the following data.

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Sample	Mean	Range
1	4.01	0.14
2	4.03	0.18
3	3.98	0.16
4	4.20	0.17
5	3.89	0.13
6	4.00	0.18
7	4.05	0.17
8	4.03	0.16
9	4.08	0.15

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a. Determine the  upper and lower control limits for the X-bar chart.

b. Determine the upper and lower a/b zone boundary for the X-bar chart.  

d. Determine the upper and lower a/b zone boundary for the R-chart.

Answer 1

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