Fifteen Samples of Size 10 Are Taken from a Stable

Fifteen samples of size 10 are taken from a stable process. The average of the sample means is 32.8, and the average range of the samples is 1.5. Use the information contained in the chart below (Table 13s.1) :

-The UCL for the three sigma R chart for the process is approximately (for a sample size of 10, D₃ = 1.777, D₄ = 0.223) :

A) 0.39
B) 0.34
C) 0.46
D) 2.67
E) 1.50