Random samples of four items are selected from a manufacturing process at regular intervals,and a certain quality characteristic is measured. After 25 samples,ΣX = 15,350 and ΣR = 411.4. To construct a mean chart,what is the value for the centerline?
A)15,350
B)614
C)411.4
D)3837.5

Question

Quizplus · Accepted Answer

The centerline of a mean chart is calculated by dividing the sum of the sample means (ΣX) by the number of samples. Here, ΣX = 15,350 and there are 25 samples. So, the centerline is 15,350 / 25 = 614.

Random Samples of Four Items Are Selected from a Manufacturing