A textile manufacturer wants to set up a control chart for irregularities? (e.g., oil? stains, shop? soil, loose? threads, and? tears) per 100 square yards of carpet. The following data were collected from a sample of twenty? 100-square-yard pieces of? carpet:
Sample Irregularities Sample Irregularities Sample Irregularities Sample Irregularities
1 10 6 17 11 16 16 12
2 16 7 8 12 10 17 6
3 15 8 8 13 15 18 12
4 5 9 12 14 6 19 8
5 9 10 8 15 8 20 15
Using these? data, set up a? c-chart with z=3. What is the UCL and LCL? (rounded to two decimal places).
Suppose that the next five samples had 16?, 12, 16?, 20?, and 15 irregularities. What do you? conclude?
A. At least one of the sample points is less than the upper control? limit, so the process is not in control.
B. At least one of the sample points is greater than the lower control? limit, so the process is not in control.
C. All of the sample points are within the control? limits, so the process is not in control.
D. At least one of the sample points is greater than the upper control limit comma so the process is not in control.At least one of the sample points is greater than the upper control limit, so the process is not in control.
E. At least one of the sample points is less than the lower control limit comma so the process is not in control.At least one of the sample points is less than the lower control limit, so the process is not in control.
F. All of the sample points are within the control limits comma so the process is in control.All of the sample points are within the control limits, so the process is in control.