Answer: the joggers average speed is 9 miles per hour.
Explanation:
A jogger runs for half an hour and a distance of 4 miles.
Speed = distance/time
Therefore, the speed of the jogger for the first half hour is
4/0.5 = 8 miles per hour
The jogger rest for one hour. Then the jogger runs for half an hour and the distance of 5 miles.
Therefore, the speed of the jogger for the second half hour is
5/0.5 = 10 miles per hour
The average speed of the jogger would be
(8 + 10)/2 = 18/2 = 9 miles per hour.