Sarah Soliz, Director of Quality Programs, Is Designing $\bar { x }$

Multiple Choice

Sarah Soliz, Director of Quality Programs, is designing $\bar { x }$ 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 $\bar { x }$ chart is _________.

A) 5
B) 26
C) 0.15
D) 11.2
E) 112