Let X be a discrete random variable with the probability mass function P(x) = kx2 for x = 2,3,4,6 (i.e., these are the only possible values of this random variable).
(a) Find the appropriate value of k.
(b) Find P(3), F(3), P(4.2), and F(4.2).
(c) Sketch the graphs of the pmf P (x) and of the cdf F (x).
(d) Find the mean μ and the variance σ2 of X.