Answer:
Julies average speed was 5 mph and her average velocity was 0 mph.
Step-by-step explanation:
The average speed is (4 mph + 6mph) / 2.
It represents Julie's speed of walking in average. If Julie had gone and returned at a speed of 5 mph she would have used the same total travel time.
The average velocity represents the difference between the initial and final position divided by the travel time. As the initial and final positions are the same, the average velocity is zero.