3. 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 similar sized hospital and is given in the following probability table. 5r 0 1 2 3 4 5 6 P[:z:) 0.15 0.20 0.34 0.10 0.06 0.05 0.01 Find the {a average number of times the helicopter is used to transport critical patients each month. (b) variance of the number of times the helicopter is used to transport critical patients. (c) standard deviation of the number of times the helicopter is used to transport critical patients. 4 (d) probability that the helicopter will not be used at all during a month to transport critical patients. (e) probability that the helicopter will be used at least once to transport critical patients. (f) probability that the helicopter will be used at most twice to transport critical patients (g) probability that the helicopter will be used more than three times to transport critical patients