Sunday

April 20, 2014

April 20, 2014

Posted by **Koia** on Thursday, May 10, 2012 at 3:23am.

- Math -
**MathMate**, Thursday, May 10, 2012 at 7:34amThe geometric distribution gives the probability of getting a success at the xth trial:

P(X=x)=Px(x)=(1-p)^(x-1)p

The probability of getting the first success in n trials is therefore the sum of the above, or

P(n)=Σ(1-p)^(n-1)p

=pΣ(1-p)^(n-1) (geom seq.)

=p(1-(1-p)^n)/p

=1-(1-p)^n

So

P(1)=1/6

P(2)=11/36

...

P(5)=4651/7776=0.598

P(10)=50700551/60466176=0.838

P(13)=11839990891/13060694016=0.906

P(15)=439667406451/470184984576=0.939

...

- Math -
**Koia**, Sunday, May 13, 2012 at 12:06amit really make me confusing what you are mention, how could i describe what you did

- Math -
**MathMate**, Sunday, May 13, 2012 at 10:17pmIf you have not done the geometric distribution at school, you need to read up about it before. I agree that it is not obvious if you have not done the distribution before, or if you have not done summation of geometric series before.

In my calculations above,

P(1) is the probability of obtaining at least one favourable outcome with one trial (throw of die)

P(2) is the probability of obtaining at least one favourable outcome (throwing a six) with 2 trials.

...

P(n) is the probability of obtaining at least one favourable outcome with n throws of the die.

It turns out that with 13 throws, the probability of getting at least "six" once is 0.9, as shown above.

**Related Questions**

statistics - A fair die is tossed and the number facing up is noted. If the ...

Probability - Suppose that a fair die is tossed. What is the expected number of ...

Statistics and Probability - One six-sided fair die is rolled, and one two-sided...

Statistics - A die that is fair will have each face of the die come up one-sixth...

MATH - In a board game, tossing an even number on the die means taking 5 spaces ...

math - Consider the experiment of simultaneously tossing a fair coin and rolling...

math - 1.A red die and a blue die are tossed. What is the probability that the ...

math fair - The game of dots is played by rolling a fair die and receiving $1 ...

Algebra - A red die and a blue die are tossed. What is the probability that the ...

Math-Fair Game question - the game of dots is played by rolling a fair die and ...