For an x-bar chart where the standard deviation is known, the Upper Control Limit

		is 3 . below the mean of sample means for a 3 control chart.
		is 3 . / n above the mean of sample means for a 3 control chart.
		Cannot be calculated unless the average range is known.
		is 3 . / n below the mean of sample means for a 3 control chart.
		is 3 . above the mean of sample means for a 3 control chart.

2.

A company wants to develop control charts to assess the quality of its steel plate. They take ten sheets of 1" steel plate and compute the number of cosmetic flaws on each sheet. Each sheet is 20' by 100'. Is the process in control assuming that Z=3?

Sheet	Number of flaws
1	1
2	0
3	5
4	0
5	1
6	5
7	0
8	2
9	0
10	1

		Yes, because all data points are within the control limits.
		No, because one data point exceeds the upper control limit which is between 4.5 and 5.
		No, because two data points exceed the upper control limit which is between 4.5 and 5.
		No, because two data points exceed the upper control limit which is between 4 and 4.5.
		No, because one data point exceeds the upper control limit which is between 4 and 4.5.