Question for Phil R.

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Question for Phil R.
Message posted by Bill on November 2, 2000 at 12:00 AM (ET)

Phil (or others),

Do you have a reference that describes the Poisson distribution and gives examples in laymen terms. Most references I have are very short on readable details and give rather obscure examples, if any. Thanks.

READERS RESPOND:
(In chronological order. Most recent at the bottom.)

Re: Question for Phil R.
Message posted by Nancy Diehl on November 3, 2000 at 12:00 AM (ET)

References for the Poisson Distribution:
If you can find "Statistics for Management and Economics" by Mendenhall, Reinmuth, Beaver - it's an excellent source and gives
good examples of the application of the Poisson. Most of these texts explain the Poisson formula in terms of
"mu-to-the-x,times,e-to-the-minus-mu,over,x-factorial". However, if you can get a hold of the Juran "Quality Control Handbook"
it explains the use of the Poisson in terms of "np" instead of mu, which is really helpful when your "n" is substantially
large. In addition, this Handbook, in the back, has Poisson tables to make it easy to look up the cumulative probabilities.
For example, an earlier submitted question here about the Poisson, where np=1%x1000=10 and the question asked for the probability
x was >= 5, you would have to calculate 1-Pr[(x=0)+(x=1)+(x=2)+(x=3)+(x=4)] or if you had these Poisson cumulative probability tables
you could look it up in the table for np=10 at x=4 and get a cumulative prob of .0293, rather than have to apply the formula 4 times
by hand. Just a thought.....

Re: Question for Phil R.
Message posted by JG on November 3, 2000 at 12:00 AM (ET)

One way of explaining the poisson
distribution is to say that it approximates the binomial when p is very small, n very large, and n*p=some constant. Also, the binomial is the distribution
you get if you count heads for a coin with p for heads, 1-p for tails.

Re: Question for Phil R.
Message posted by Phil on November 3, 2000 at 12:00 AM (ET)

The Mendenhall book is probably as good as anything, but most any decent statistics text will cover the Poisson reasonable well. "Probability and Statistics for Engineers" by Walpole & Myers, 6th ed. p. 135 is pretty good.

The Poisson is one of the basic probability distributions taught in basic statistic classes.

Books on "queueing theory" and "probability models" will have a more mathematical view.

Good luck!

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