Re: Simple Probability Question (that I have no idea how to answer)
[ QUOTE ]
On average, this result should happen once every 270 sets of four tournaments (100%/0.37%). So if you played 270 sets of four, it should have happened once. There's a 50% chance that it would have happened twice.
[/ QUOTE ]
This is not correct, though I agree with the 0.37%.
(0.1)^4 + 4*0.9*(0.1)^3 = 0.37%
If the probability of it occuring at least twice in N trials is 0.5, then the probability of it occuring 0 or 1 time in N trials is 0.5.
(1-0.0037)^N + N*(0.0037)*(1-.0.0037)^(N-1) = 0.5
Solving this for N gives N = 453, so we must play 453 sets of four tournaments. I used the Excel goal seek function to find this solution, or you can use trial and error. If you set N = 270, there will only be a 26.4% chance of it happening twice.
|