Problem 5 (n points each.) A modem transmits a (+2) voltage signal into a channel. The channel adds to this signal a noise term that is drawn from the set {1], 1,-2, 3} with respective probabilities {dill}, 3f1, jll}, 111113}. it} Find the pmfot' the output Y of the channel b} What is the probability that the output of the channel is equal to the input of the channel? c} What is the probability that the output of the channel is positive