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## #1 2006-05-06 08:30:26

amit
Guest

### probability question

you thraw 1 dice until you get K times the number '6'
X = the number of your thraws.
what is P(X) ?

## #2 2006-05-06 09:35:20

Patrick
Real Member
Registered: 2006-02-24
Posts: 1,005

### Re: probability question

Are you looking for the probability to get 6? I don't quite get the question..

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## #3 2006-05-06 21:44:00

George,Y
Member
Registered: 2006-03-12
Posts: 1,306

### Re: probability question

When X is less than K, the probability is 0,
Else Binomial distribution would be the answer.

for a single experiment,
P(dice showing 6)=1/6
P(dice not showing 6)=5/6

X'(y-Xβ)=0

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## #4 2006-05-06 22:50:40

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

### Re: probability question

George, Y is right. If X is not an integer or is less than K, then the answer is 0.

Otherwise, it would be [sup]X[/sup]C[sub]K[/sub] * (1/6)[sup]k[/sup] * (5/6)[sup](X-K)[/sup]

{Arbitrary text goes here because the [sub] tag messes up otherwise. }

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