Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I have expressions for marginal probability distributions p(a) and p(b). The joint probability distribution p(a,b), if I understood correctly, can be obtained by the product p(a)*p(b). I need to find the conditional probability P(Y|a,b). What information about Y is needed for doing this? If the probability distribution of Y is simply given as p(Y), what would be the expression for conditional probability?

share|improve this question
1  
What is Y in terms of a and b? –  oks Feb 14 '13 at 8:34
2  
p(A=a,B=b) = p(A=a)*p(B=b) only if A and B are independent. –  oks Feb 14 '13 at 8:36
    
I am trying to understand the theory behind a specific mathematical derivation, so I am not yt sure what is Y in terms of a and b, but assuming p(Y) is known simply as p(Y) and p(a,b) = p(a)*p(b), what should be done to get P(Y|a,b)? Or is the given data not enough to determine this conditional probability? –  user13267 Feb 14 '13 at 9:33
add comment

1 Answer 1

I need to find the conditional probability $P(Y|a,b)$. What information about $Y$ is needed for doing this?

One way or another, the joint distribution of $(Y,a,b)$.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.