Pembicaraan:Masalah Monty Hall

Penjelasan

I'm sorry I don't understand your language, but Isee the same picture as in the English Wikipedia as explanation so I suppose the given explanation is not correct. It gives the solution to a slightly, but essential other problem. The real problem as stated has the condition that the door that is chosen and the door that is opened and revealing a goat are both known to the player. This excludes possibilities in which the other door is opened. Many people does not see the difference with the problem, in which the chosen door is known, but the presentator explains his plans to the player, and before opening one of the othere doors, asks the player what he intends to do if a door is opened. The presented solution is the right one for the last case, but not for the real problem.

In more formal mathematics: Let X be the door behind which the car is, Y the door chosen by the player and M the door opened by the presentator, then when Y=1 (conditional that door 1 is initially chosen):

$P(X=2|M=3,X\neq 3)={\frac {P(M=3|X=2)P(X=2)}{P(M=3,X\neq 3)}}=$

${\frac {P(M=3|X=2)P(X=2)}{P(M=3,X=1\cup M=3,X=2)}}={\frac {\frac {1}{3}}{{\frac {1}{2}}\times {\frac {1}{3}}+1\times {\frac {1}{3}}}}={\frac {2}{3}}$

Nijdam (bicara) 22:23, 7 Februari 2009 (UTC)

(404 • s)

Gunakan bahasa Indonesia

08:44, 18 Februari 2009 (UTC)