Originally Posted by

**bartoncl** P(A U B) = .7 P(A U compliment of B) = .9

Find P(A)

I've racked my brain and cannot come up with an answer.

This is all I've managed to calculate, perhaps I'm just missing a connection.

P(A U compliment of B) = P(compliment of B)

P(B) = 1 - P(compliment of B) = .1

P(compliment of A intersect compliment of B) = 1 - P(A U B) = .3

P(A intersect compliment of B) = P(A U B) - P(B) = .6

P(A|compliment of B) =

P(A intersect compliment of B) / P(compliment of B) = 2/3

"This last one establishes dependence."

That is all I could come up with.