Verify that the function f(x) = (3/4)(1/4)^x, x = 0, 1, 2,... is a probability mass function. Determine the requested probabilities:
(a) P(X = 2)
(b) P(X <= 2)
(c) P(X > 2)
(d) P(X >= 1)
Then determine the cumulative distribution function for the random variable.