9.4 Consider the procedure described in Adaptive Playout Delay for estimating average delay di. Let 3 3 r ? t be the most recent sample delay, let 2 2 r ? t be the next most recent sample delay, and so on. For a given audio application, suppose three packets have arrived at the receiver with sample delays 1 1 r ? t , 2 2 r ? t , and 3 3 r ? t . Express the estimate of delay d in terms of u and the three samples.(reff :james kurose computer networking 7th edition )