## RaphaelFilgueiras Group Title What is the summation of: one year ago one year ago

1. RaphaelFilgueiras

|dw:1357507840261:dw|

2. SmoothMath

$\Large \left(\begin{matrix}n \\ i\end{matrix}\right)^2$

3. RaphaelFilgueiras

this is the real problem

4. satellite73

pretty sure it is $$\dbinom{2n}{n}$$ but i can't off the top of my head remember why

5. RaphaelFilgueiras

i want to find pi0

6. RaphaelFilgueiras

@satellite73 the book says something about hypergeometric distribuction

7. RaphaelFilgueiras

actually (2n,n) is just pi0

8. satellite73

i am afraid i do not know the meaning of $$\pi_0$$

9. RaphaelFilgueiras

it is just a probability

10. RaphaelFilgueiras

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11. satellite73

oh i see you are supposed to prove that it is a probability by showing the sum is one hmmm

12. RaphaelFilgueiras

no i have to find pi0,i know it's a probability

13. satellite73

i guess i am useless here sorry

14. RaphaelFilgueiras

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15. RaphaelFilgueiras

acctualy you are rigth were the hell this (2n,n) come from?