Problem 1: Statistical Multiplexing. (Chapter 1, Problem P8) Suppose users share a 3 Mbps link. Also suppose that each user transmits only for 10% of the time at 150kbps, and is idle the remaining time (a) When circuit-switching is used, how many users can be supported? (b) For the remaining of the problem, assume packet-switching. (i) Find the probability that a given user is transmitting. (ii) Suppose there are N 120 users. What is the probability that at any given time exactly n users transmit simultaneously? (ii) What is the probability that there are 21 or more users transmitting simultaneously