Suppose X is a continuous random variable with a density function:
f(z) = 3r?e^(-2z), z > 0
otherwise
Find the moment generating function (mgf) of X and, using the mgf, find the mean and variance of X.
Select one:
a) E(X) = 9 and Var(X) = 9
b) E(X) = 3 and Var(X) = 3
c) E(X) = 9 and Var(X) = 3
d) E(X) = 3 and Var(X) = 9