At 08:22 AM 10/28/2009, Jeph Herrin wrote:
Prob(rain) = 7/120
Prob(no rain) = 113/120
X=days it rains on hat
Prob(X=3)=c(4,3)*(7/120)^3*(113/120)^1
=4*0.0001985*0.94
=0.0007477
not much chance!
Don't the probabilities change though? e.g. if it rains on the first
day, then the probability of rain on the 2nd day is 6/119.
Maybe Maarten can just run a couple million simulations for us...
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Richard Williams, Notre Dame Dept of Sociology
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