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Problem 6 [10 points = 5 + 5] Consider a queuing system with a single server that is functioning under stationary distribution. Customer arrivals form a Poisson process that has rate A = 3 per hour. Service times are independent exponentially distributed with average = p'1 = 10 minutes. Focus on the departure process, {D(t) : t 2 0} assuming that the system is operating under stationary distribution. 1. Determine expected number of customers departing from this system within the time interval (in hours) from t = 2 till 15 = 5. 2. Find the covariance (time is measured in hours) Cov [13(3) 13(1), 13(5) 13(2)]