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Where was I?
OK, so what's the chance of getting a single AA or KK in 2100 hands?
Really, really low.
(2100 p 1) * (.00905) * (.99195) ^ 2099
(note that Excel has a BINOMIAL function which does this for you)
P(1) = 9.8 x 10^-08. Or .000000098, ~ 1 in 10 million
Now, P(5 KK or AA)
(2100 p 5) * (.00905)^5 * (.99195) ^ 2095
P(5) = .00011, or 1 in 9085. Which means my original post of 1 in 1 million is way, way, WAY off.
Hmmm... and I did both in excel. I must have entered something wrong.
Well, I either get the above for P(5) directly, and summing P(4,3,2,1) I get P = .00019, which is 1 in 5267
OR if I use the cumulative binomdist function in excel for 5/2100,
I get P = .000146, which is 1 in 6855
I think it's a rounding error, and probably 1/6855 is right. I didn't save my file the first time, but I think it's way wrong.
Conclusion:
1) Always check your work (better yet, have someone else do it)... funny that my P(KK/AA) = 1/110 was challenged by 1/2 a percent,. but no one noticed that my actually calculation was off by a factor of 20 or so.
2) littletrogdor, not as unlucky as we originally thought.
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