Hello all,
Years ago, we used to shake coins prior to conducting QR etc. anybody know of the percentages depending on how many coins were shook? I think 4 coins all coming up heads was about 6.25%, 3 coins was about 23.6% and so on...I'm not sure....an old version of 00-20-14 in the early 80's gave a break down. Could use some help here. Thanks, Steve
Yes, the normal sampling rate was using 4 coins and an item that came up 4 heads would get recalibrated by QA. The odds of 4 heads occurring was 6.25%.
If that item failed, your next 4 would get check by QA. If they passed you went back up to the normal sampling rate using 4 coins.
If one of those 4 failed, you went to an increased sampling rate using only 3 coins. The odds of 3 heads coming up then increased to 12.5%.
If you kept failing items you would go to 2 coins. The odds of 2 heads out of 2 coins is 25%.
If you bombed out there you would go to 1 coin where of course you have a 50% chance of getting a heads.
It's too early to remember all the exact details of the QA sampling system from 20 years ago but that is the quickie version.
I've seen one person at the 25% level but they didn't last long before they got reassigned to dorm monitor.
Thanks Dave...much appreciated.
We used to do that as well, as time went on we started doing it electronically and applying that to a production report that highlighted the selected items, I still have the pennies, post 1982 clad zinc and the copper is worn of in places from so much handling & tossing. Copper or Silver coin has a much nicer tone when it rings, the clad just kind of thud.