Let X be a random variable, and let a and b be constants. Say whether or not each of the following expressions is correct.

a. Var(X) = E(X 2

) − (EX)

2

.

b. E(aX +

b) = aE(X) + b.

c. Var(aX +

b) = aVar(X) + b.

d. Var(aX +

b) = Var(aX + b 2

).

e. Var(aX +

b) = a 2Var(X).

f. Var(X) = E



(X − EX)

2

.