Random Samples of Four Items Are Selected from a Manufacturing

question 33

Multiple Choice

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