Comment: I have an autographed copy of Walter Shewart's book.

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In reply to comment: Lies. Damn lies. And statistics! (see in situ)

I have an autographed copy of Walter Shewart's book.

My Grant and Leavenworth sits right next door.

I was a Manufacturing Engineer once upon a time. Control charts are great for production control. SPC charts tell you when to look for trouble because it is more likely than not.

Any ratio over 51 ratio implies that something is probably causing trouble. With machinery it could be a screw loose.

In the case of gold and silver it suggests some non-random causes, to use the lingo. Whatever is going on, it is out-of-control.

I was able to analyze the data of the MS Blaster virus, after the fact. The network traffic for the port used broke the control limits Saturday afternoon. By Monday our shop was full of computers to re-install.

You have answered one question I've long had: Do investors use these tools. Thanks for the link!

PS email received. Noted, add closing anchor. Thanks Mark.

Free includes debt-free!