Sarah Soliz,Director of Quality Programs,is designing and R charts for the rod shearing process at Stockton Steel.She has 26 samples of rod length,and each sample included measurements of 5 rods.The mean of the 26 sample means is 112 centimetres,and mean of the 26 ranges is 0.15 centimetres.The centerline for her chart is ___.
A)5
B)26
C)0.15
D)11.2
E)112

Question

Quizplus · Accepted Answer

The centerline for an R chart is the average of all the ranges, which is given as 0.15 centimeters. Since we are not given any specific target value or specification limit, the centerline of an X chart is usually the mean of all the sample means, which is given as 112 centimeters. Therefore, the correct answer is E.

Sarah Soliz,Director of Quality Programs,is Designing and R Charts for the Rod