Voting Project Needs Python People
Andrew Dalke
adalke at mindspring.com
Tue Jul 22 18:11:07 EDT 2003
Alan Dechert:
> catch it. If one percent of the electronic votes were altered (evenly
> distributed), you will find one mismatch for sure after checking only a
> dozen or two ballots.
Actually, around 70 ballots.
The odds of finding one ballot to be wrong is 1%, so there's a 99%
chance that it's unaltered. There's a 0.99*0.99 chance that two are
unaltered, and in general a 0.99**n chance that n are unaltered.
To get even odds of noticing an error requires
0.99**n == 0.5
--> log(0.99)*n == log(0.5)
>>> math.log(0.5) / math.log(0.99)
68.967563936528421
>>>
about 70 verifications.
Andrew
dalke at dalkescientific.com
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