Show that if X has a normal distribution with parameters n and m, then Y = aX+ b( a linear function of X) also has a normal distribution. What are the parameters of the distribution of Y(i.e.: E[Y] and Var[Y])? Solution If X~N(n,m) i.e. E[X]=n and Var(X)=m then aX+b will have E[aX+b] =aE[X]+b = an+b and Var(aX+b) = a^2Var(X)=a^2m, so that aX+b ~N(an+b,a^2m)..