Q1 (Joint). We know X|Y is a normal random variable with mean Y and variance 2. The probability distribution of Y is a binomial distribution with success probability 0.3 and the number of trials 5. What is the expected value of X? (The way to interpret X|Y is as follows: If Y=0, [X|Y=0] is a normal random variable with mean 0 and variance 2)

Denna får jag till 1,5 vilket ska vara rätt. När man däremot ska räkna ut variansen av X är jag helt lost. Hur gör man?