Consider the procedure described for estimating average delay di. Suppose that u=0.1. Let r1-t1 be the most recent sample delay, let     r2 -t2 be the next most recent sample delay, and so on.

a) For a given audio application suppose four packets have arrived at the receiver with sample delay r4-t4, r3-t3, r2-t2, and r1-t1. Express the estimate of delay in terms of four samples.
b) Repeat part a) for the estimate of average delay deviation