For a 3-sigma x-bar chart where the process standard deviation is known,the upper control limit:
A)is 3σ below the mean of sample means for a 3σ control chart.
B)is 3σ above the mean of sample means for a 3σ control chart.
C)is 3σ/ below the mean of sample means for a 3σ control chart.
D)is 3σ/ above the mean of sample means for a 3σ control chart.
E)cannot be calculated unless the average range is known.

Question

For a 3-sigma x-bar chart where the process standard deviation is known,the upper control limit:
A)is 3σ below the mean of sample means for a 3σ control chart. 
B)is 3σ above the mean of sample means for a 3σ control chart. 
C)is 3σ/ below the mean of sample means for a 3σ control chart. 
D)is 3σ/ 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 a 3-sigma x-bar chart where the process standard deviation is known,the upper control limit:
A)is 3σ below the mean of sample means for a 3σ control chart. 
B)is 3σ above the mean of sample means for a 3σ control chart. 
C)is 3σ/ below the mean of sample means for a 3σ control chart. 
D)is 3σ/ above the mean of sample means for a 3σ control chart. 
E)cannot be calculated unless the average range is known.

For a 3-Sigma X-Bar Chart Where the Process Standard Deviation