Homework Assignment 5


Problem 3-4.
Solution:

= 124.93
Ri is calculated as following:


= 3.45
For sample size 4, A2 = 0.729, D3 = 0, D4 = 2.282.
= 124.93+0.729*3.45 = 127.45
= 124.93
= 124.93-0.729*3.45 = 122.41
= 2.282*3.45 = 7.87
= 3.45
= 0
The chart and R chart is as following:

According to these two charts, this process is statistical control.