1.7. Suppose that customers arrive at a facility according to a Poisson process having rate A = 2. Let X(t) be the number of customers that have arrived up to time t. Determine the following probabilities and conditional probabilities: (a) Pr{X(1) = 2}- (b) Pr{X(l) = 2 and X(3) = 6}. (c) Pr{X(1) = 2X(3) = 6}. (d) Pr{X(3) = 6X(1) = 2}