# Thread: 2D table of random variables

1. ## 2D table of random variables

We have two random variables.

I would like to know how to get the probabilities p1, p2, p3 ... of two random variable in a table?

I just know that the sum of all probabilites p1, p2, p3... must be equal to 1!

2. ## Re: 2D table of random variables

Originally Posted by Nforce
We have two random variables.

I would like to know how to get the probabilities p1, p2, p3 ... of two random variable in a table?

I just know that the sum of all probabilites p1, p2, p3... must be equal to 1!
Just let $m=1,~2,~3~\&~n=1,~2,~3$ form a matrix $J=\left(a_{m,n}\right)$ where $a_{m,n}=P(x_m)\cdot P(y_n)$.

3. ## Re: 2D table of random variables

Thank you, the sum is really 1. Can I ask is this a general rule? Is correlation or dependence effect this?