The queuing model (only the direction to the Internet) for a router is described in the figure below. It can be shown that if the packet length follow a negative expotential distribution, the average number of packets, denoted by N bar an arriving packet will find in the router (including the one in the transmitter) can be described by the following simple formula: N bar = rho/1 - rho where rho = lambda x bar and lambda is the average packet arrival rate (packets/sec), x bar is the average transmission time of a packet. Rho is often called the average utilization of the link connecting to the Internet. The average waiting time W for a packet staying in the queue w = N bar x bar. (a) Assume the average packet length is 1200 bits. Compute the average transmission time x bar. (b) Assume the average arrival rate is 1000 packets/sec, 1300 packets/sec, and 1600 packets/sec. Compute the average packet delay for the three cases