Answer:
[tex]Distance=0.104\times n (miles)[/tex]
Explanation:
When we hear the echo the sound would have traveled twice between the person and the wall.
Thus if we hear an echo after n seconds we have
[tex]2\times Distance= Speed\times Time\\\\\therefore Distance=\frac{0.208miles/sec\times nsecs}{2}\\\\Distance=0.104\times n (miles)[/tex]