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 upper control limit for her R chart is ___.
A)0.150
B)10.57
C)0.317
D)2.114
E)0.713

Question

Quizplus · Accepted Answer

To find the upper control limit (UCL) for the R chart, we need to use the formula: 
UCL = D4*Rbar, where Rbar is the mean range and D4 is a constant factor based on the sample size (in this case, n=5).
From statistical tables, we can find that for n=5, D4=2.114.
Therefore, UCL = 2.114 * 0.15 = 0.317 cm. 
So, the best choice is C.

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