Discrete random variables $X$ and $Y$ have the joint density shown in the table below.
$ \ \ \ \ X \ 1 \ \ \ 2$
$Y$
$1 \ \ \ \ \ \ \frac{1}{10} \ \ \ \frac{2}{10}$
$2 \ \ \ \ \ \ \frac{3}{10} \ \ \ \frac{4}{10}$
What is the conditional density of $Y$ given $X = 1$?
What is the procedure for doing this problem? I have an exam tomorrow and we never covered this in the lectures. I have just found it on an old exam paper which means it could potentially be on tomorrows exam.