A regional hospital is considering the purchase of a helicopter to transport critical patients. The relative frequency of X, the number of times the helicopter is used to transport critical patients each month, is derived for a similarly sized hospital, and is given in the following probability distribution. (15 pts) Number of times used per month f(x) 0.15 1. 0.22 2 0.34 0.14 4 0.08 5 0.07 a) What is the expected number of times the helicopter is used to transport critical patients each month? b) Find the standard deviation of the number of times the helicopter is used to transport critical patients each month. c) Find the probability that the helicopter will be used more than 2 times to transport critical patients in a month. d) True or False: The number of times the helicopter is used each month follows a discrete uniform distribution (Explain).