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Path: utzoo!watmath!clyde!akgua!sdcsvax!sdcrdcf!hplabs!hao!kpnoa!sharp
From: sharp@kpnoa.UUCP
Newsgroups: net.physics
Subject: Coin flips
Message-ID: <328@kpnoa.UUCP>
Date: Mon, 14-May-84 12:35:27 EDT
Article-I.D.: kpnoa.328
Posted: Mon May 14 12:35:27 1984
Date-Received: Thu, 17-May-84 05:26:58 EDT
Organization: Natl. Optical Astronomical Obs.   Tucson AZ  USA
Lines: 19

<>
Ethan's comment last month on the rational way to approach a series of coin
tosses that went T,H,T,H,H,H,H, and that he'd choose heads because the coin
might be biassed, brings to mind a whole branch of probability that I've
never had time to investigate.  Perhaps someone out there knows ....
    The question is this: what is the probability that the coin IS biassed ?
In general, given a sequence with a predicted a priori probability of any
particular event (for a coin, prob=0.5 of either head or tail), what can we
say about this hypothesised probability ?  Is there a statistical or
probabilistic test which gives us a level of confidence in our assumed
probability given a realisation of the sequence ?
    After all, I remember being in a fairground with a machine which was stuck,
and always came up on one of three positions out of more than a dozen.  It did
not take us long to empty the machine, since realising the problem was easy !!

    While I'm soliciting information from the net, comments about the book
"The Fifth Generation" and its remarks about nets will be welcome.

     Nigel Sharp  (noao!sharp, for a little while yet kpno!sharp)