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 upper control limit for her $\bar { x }$ chart is ________.
A)112.09
B)5.087
C)26.087
D)115.90
E)110.09

Question

Quizplus · Accepted Answer

The upper control limit (UCL) for the $\bar{x}$ chart can be calculated using the formula: UCL = $\bar{x}$ + A2 * R̄, where $\bar{x}$ is the overall mean of the sample means, R̄ is the mean range, and A2 is a constant that depends on the sample size (n). For n=5, A2 is typically 0.577. Given $\bar{x}$ = 112 inches and R̄ = 0.15 inch, UCL = 112 + (0.577)(0.15) = 112.0865, which rounds to 112.09.

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

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