A poison is injected into a rat. With probability 3/4, the rat will die immediately after the injection. If the poison does not instantly kill the rat, the rat's remaining lifetime is uniformly distributed over a period of four hours. Let X be the amount of time it takes for the poison to kill the rat. (b) Determine the survival function for X. (c) Compute E (X) using the Law of the Unconscious Statistician. (d) Compute E (X) using the survival function