Originally Posted by

**statsaway** Hello,

This is my first post here. I'm in need of some help understanding these three problems.

#1. Determine all joint probabilities from the following.

P(A)= .8

P(BlA)= .4

P(Ac)= .2

P(BlAc)=.7

read the letter c as complement.

From this I figure I need to find the following probabilities:

P(A and B), P(A and Bc), P(Ac and B), and P(Ac and B). The c's should be read as complement.

So, how do I do this? I'm kind of confused at this point. I'm sure I have to draw a table.. but I'm not sure how.. please, if you can.. help me.

#2. Given the following probabilities, draw a probability tree to compute the joint probabilities.

P(A)= .8

P(BlA)= .3

P(Ac)= .2

P(BlAc)=.3

Again..I feel that I need to find the probabilities of the following for the tree:

P(A and B), P(A and Bc), P(Ac and B), and P(Ac and B). The c's should be read as complement.