For an x-bar chart where the standard deviation is known, the Upper Control Limit
A) is 3 . σ below the mean of sample means for a 3σ control chart
B) is 3 . σ above the mean of sample means for a 3σ control chart
C) is 3 . σ/ below the mean of sample means for a 3σ control chart
D) is 3 . σ/ above the mean of sample means for a 3σ control chart
E) Cannot be calculated unless the average range is known.

Question

For an x-bar chart where the standard deviation is known, the Upper Control Limit
A) is 3 . σ below the mean of sample means for a 3σ control chart 
B) is 3 . σ above the mean of sample means for a 3σ control chart 
C) is 3 . σ/ below the mean of sample means for a 3σ control chart 
D) is 3 . σ/ above the mean of sample means for a 3σ control chart 
E) Cannot be calculated unless the average range is known.

Quizplus · Accepted Answer

The Answer of For an x-bar chart where the standard deviation is known, the Upper Control Limit
A) is 3 . σ below the mean of sample means for a 3σ control chart 
B) is 3 . σ above the mean of sample means for a 3σ control chart 
C) is 3 . σ/ below the mean of sample means for a 3σ control chart 
D) is 3 . σ/ above the mean of sample means for a 3σ control chart 
E) Cannot be calculated unless the average range is known.

For an X-Bar Chart Where the Standard Deviation Is Known