75) Repeated sampling of a certain process shows the average of all sample ranges to be 1.0 cm. The sample size has been constant at n = 5. What are the 3-sigma control limits for this R-chart?

80) Larry's boat shop wants to monitor the number of blemishes in the paint of each boat. Construct a 3-sigma c-chart to determine if their paint process is in control using the following data.

Sample Number	Number of Defects
1	3
2	4
3	2
4	1
5	3
6	2
7	1
8	4
9	2
10	3

Answer:

Total units sampled
Total defects
Defect rate, c-bar
Standard deviation
z value
Upper Control Limit
Center Line
Lower Control Limit