Re: Developer of XmR chart

[John <JohnEGibson@comcast.net>]

Bob
Your suggestion was a big help.

My 1956 edition of the Western Electric Handbook has XmR on page 21.
Under Acknowledgements on p 275, we find for pages 12, 17, 20 and 21 the
control chart factors and formulas.
Taken by permission from the

- ASTM Manual on Quality Control of Materials, STP 15-C, copyright 1951,
American Society for Testing Materials, Philadelphia, Pa.

¨ Some of this material was originally published in British Standards 600:
1935, (E. S. Pearson, "The Application of Statistical Methods to Industrial
Standardization and Quality Con­trol") and in

¨  British Standards 600R: 1942 (B. P. Dudding and W. J. Jennett, "Quality
Control Charts"), British Standards Institute, London, England.

Maybe we have an English origin.

Thanks
John