A psychologist determined that the number of sessions required to obtain the trust of a new patient is either 1, 2, or 3. Let z be a random variable indicating the number of sessions required to gain the patient's trust. The following probability function has been proposed. f(z) = for z = 1,2, or 3 a. Consider the required conditions for a discrete probability function, shown below. f(2) 0 (5.1) (7) = 1 (5.2) b. What is the probability that it takes exactly 2 sessions to gain the patient's trust (to 3 decimals)? c. What is the probability that it takes at least 2 sessions to gain the patient's trust (to 3 decimals)?