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Subject: Re: I would call this SPORT christophe !

Author: Danniel Corbit

Date: 07:47:58 08/09/98

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On August 09, 1998 at 09:59:47, Christophe Theron wrote:
[snip]
>NEVER. 10 games is NOT ENOUGH.
>
>I have found that a 30 games match has a +/- 5% error margin. That is a 50%
>result can mean 45% to 55%.
[snip]
The book "Statistical Methods" by Pfaffenberger & Patterson [ISBN 0-256-03664-0]
makes the following quote on pages 504 & 505:
"Hypothesis tests concerning the population variance or the population standard
deviation are based on the X^2 distribution first introduced in Chapter 9. These
tests assume that the population random variable X is normally distributed. If X
is not normally distributed, but is approximately so, then these tests should be
used only for "large" samples (n = 100 or more is often required). The degrees
of freedom for tests concerning the population variance and the population
standard deviation are df = n - 1."

So we might take 100 as a _minimum_ number of trials to get a result about an
unknown population.  Interestingly, they supply detailed formula for
determination of the smallest sample size you should use for testing hypothesis.
 On pages 503 & 504 the sample sizes worked out in the example problems were 451
and 266.

So you are very, very correct.  A sample of ten games probably shows us very
little.



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