Give an example of a random variable (i.e. give the range of values it takes and its p.m.f.) with the following properties: EX = 4, VAR(X)=4. Now give an example of a random variable with a different p.m.f. than the first one you gave, but that still has EX = 4, VAR(X)=4. So this means then E(X) = E(X^2) - (E(x))^2 right? I'm not sure if this is the way I should approach the problem?