# Thread: X and Y joint pdf probability question

1. ## X and Y joint pdf probability question

If X and Y have the joint pdf
$f_{X,Y}(x,y) = 2, \ \ \ 0 < x < y < 1,$
then find $P (0 < X < 0.5 | y = 0.75)$

2. Originally Posted by wik_chick88
If X and Y have the joint pdf
$f_{X,Y}(x,y) = 2, \ \ \ 0 < x < y < 1,$
then find $P (0 < X < 0.5 | y = 0.75)$
What thoughts have you had? Where are you stuck?

3. i havent ever done a joint pdf question where the probability has the "given y = ..." in it!

4. Originally Posted by wik_chick88
i havent ever done a joint pdf question where the probability has the "given y = ..." in it!
In the first instance, I suggest you refer to your class notes or textbook for the definition of the conditional density of X given Y = y ....