A hospital researcher is interested in the number of times the average postop patient will ring the nurse during an 8hour shift. The random variable X is likely to assume the values 0, 1, 2, 3, and 4 with probabilities given as follows x 0 1 2 3 4 Probability 0.14 0.26 0.22 0.25 0.13 a) What is the probability that the number of times the average postop patient will ring the nurse during an 8hour shift is at most 3? b} Calculate the expected number of times the average postop patient will ring the nurse during an 8-hour shift