Use the probability mass function in Exercise 3-11 to determine the following probabilities:
(a) P (X < 2)
(b) P (0.5 < X < 2.7)
(c) P (X > 3)
(d) P (0 < X < 2)
(e) P (X = 0 or X = 2)
Verify that the following functions are probability mass functions, and determine the requested probabilities.