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 inches,and mean of the 26 ranges is 0.15 inch.The centerline for her R chart is ____.
A) 0.15
B) 26
C) 5
D) 112
E) 15

Question

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 inches,and mean of the 26 ranges is 0.15 inch.The centerline for her R chart is ____.
A) 0.15 
B) 26 
C) 5 
D) 112 
E) 15

Quizplus · Accepted Answer

The centerline for the R chart is the average range, which is given to be 0.15 inch. Therefore, the answer is A) 0.15. None of the other values given are appropriate for the centerline of an R chart.

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