Question

Twelve samples, each containing five parts, were taken

from a process that produces steel rods. The length of each rod in the

samples was determined. The results were tabulated and sample

means and ranges were computed. The results were:

Sample Sample Mean (in.) Range (in.)

1 10.002 0.011

2 10.002 0.014

3 9.991 0.007

4 10.006 0.022

5 9.997 0.013

6 9.999 0.012

7 10.001 0.008

8 10.005 0.013

9 9.995 0.004

10 10.001 0.011

11 10.001 0.014

12 10.006 0.009

a) Determine the upper and lower control limits and the overall

means for -charts and R-charts.

the answer states an equation using numbers i know how to get except .577

how did you get the .577

Answer 1