a=28 and moo is zero, I mean E(X), sry

and the distribution of X is...

P(X=-3)=P(X=3)=9/28

P(X=-2)=P(X=2)=4/28=1/7

P(X=-1)=P(X=1)=1/28

NOW, let

So, P(Y=9)=P(X=-3)+P(X=3)=18/28=9/14

P(Y=4)=P(X=-2)+P(X=2)=2/7

and P(Y=1)=P(X=-1)+P(X=1)=1/14

E(Y)= 9(9/14)+4(2/7)+1(1/14), which better be the variance of X.