Re: Measuring Turquoise Underwear

On Sat, 05 May 2007 13:16:07 +0100, Evil Nigel <useweb@xxxxxxxxxx>
wrote:

To recap:

1) I hypothesised a potential mathematical mechanism to explain a small
amount of predictability in lottery draws based on past data. I
implemented a spread*** to generate predictions, ranking each of the
49 balls of the UK lottery. I checked the rankings of the drawn balls,
and no predictive effect was apparent. However, it seemed to my visual
inspection that the rankings of the drawn balls tended to be widely
dispersed.

2) For each of the approx 14 million possible 6/49 combinations, I
calculated the population standard deviation. Then I calculated the
average of the 14 million standard deviations, obtaining a result of
just over 12.

Please explain the formula used for std.dev. and what book you used
The std.dev. for sums in the 6/49 game is 32.8, and the std.dev. for
49 integers is 14.14. Where does 12 come from?

Stig Holmquist>
3) I calculated the population standard deviations of the ball rankings
of successive lottery draws, and using a formula hoicked from a stats
book, evaluated the probability that these came from a population with
the mean calculated in 2), using a 2-tailed t-test. Currently p = 0.000808.


I'm a long way from certain that the above tests are statistically valid
- do any math gurus have any comments? The population standard
deviations of the 14 million combos are not a normal distribution - the
minimum is probably found in 44 cases; 1-6, 2-7 ... 44-49. I guess the
maximum is probably only found in one case: 1,2,3,47,48,49.

I once found a web site that allowed you to type in a p value and
returned you an equivalent number of standard deviations, and vice
versa. Unfortunately I can't remember the URL and a quick google didn't
disclose it. If anyone knows of a website offering this facility, I'd be
grateful. Most sites just seem to offer a table, usually giving up at 3
SDs. As long-term subscribers and correspondees know, I've had a number
of healthy-looking systems keel over and die after reaching 3.5 SDs or
so, so I'm not going to blow any trumpets until at least 4 SDs.

Evil Nigel
.

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