Sample means and ranges were obtained for five samples of 10 units per sample from a production process. Assume the process was considered to be in control during the period these samples were collected. The results are as follows:

-What is the central line of the X bar chart for this process?
A)10.12
B)10.28
C)10.20
D)9.45
E)9.75

Question

Sample means and ranges were obtained for five samples of 10 units per sample from a production process. Assume the process was considered to be in control during the period these samples were collected. The results are as follows:
 
-What is the central line of the X bar chart for this process?
A)10.12 
B)10.28 
C)10.20 
D)9.45 
E)9.75

Quizplus · Accepted Answer

The central line of an X bar chart is the average of the sample means. Without specific data, the choice closest to a typical average value is selected, which is 10.20.

Sample Means and Ranges Were Obtained for Five Samples of 10