The mean of the sample means and the pooled standard deviation of 25 samples of size 4 taken from a production process under control are found to be 150 and 10,respectively.The centerline for the $\bar { x }$ chart is:
A) 150
B) 100
C) 250
D) 6

Question

Quizplus · Accepted Answer

The centerline of the $\bar {x}$ chart is simply the mean of the sample means, which is given as 150. Therefore, the correct answer is A) 150.

The Mean of the Sample Means and the Pooled Standard xˉ\bar { x }xˉ

The Mean of the Sample Means and the Pooled Standard $\bar { x }$