Use the following table to answer the question(s) below.

-A machine shop owner wishes to monitor the diameter of an engine boring operation where the piston bore should be 4.25". He obtains 8 samples of 5 and records the data in the table above. What should the center line be for a chart that monitors process dispersion?
A) 0.50
B) 0.55
C) 0.60
D) 0.69
E) 0.80

Question

Use the following table to answer the question(s) below.
 
-A machine shop owner wishes to monitor the diameter of an engine boring operation where the piston bore should be 4.25". He obtains 8 samples of 5 and records the data in the table above. What should the center line be for a chart that monitors process dispersion?
A) 0.50 
B) 0.55 
C) 0.60 
D) 0.69 
E) 0.80

Quizplus · Accepted Answer

The center line for a chart that monitors process dispersion is calculated by taking the average of the sample means. 
The average of the sample means is calculated as (3.968 + 4.055 + 4.039 + 4.047 + 4.057 + 4.041 + 4.052 + 4.042)/8 = 4.045. 
The center line should be 4.045. 
The answer closest to this value is D, 0.69.

Use the Following Table to Answer the Question(s) Below