Exercise 5.4. In parts (a)–(d) below, either use the information given to determine the distribution of the random variable, or show that the information given is not sufficient by describing at least two different random variables that satisfy the given condition. (a) X is a random variable such that X(t) = e6t2 when |t| < 2. (b) Y is a random variable such that MY (t) = 2 2−t for t < 0.5. (c) Z is a random variable such that MZ(t) = [infinity] for t ≥ 5. (d) W is a random variable such that MW(2) = 2.