Answer:
The average speed over the interval from 9 A.M. to 3 P.M. is 2.5 mph.
Step-by-step explanation:
We can calculate the average speed as:
s = (s₁ + s₂) / n = (5 mph + 0 mph) / 2 = 2.5 mph
where:
s=average speed over the entire interval (9 A.M. to 3 P.M.)
s₁: average speed during the hiking (interval from 9A.M. to 12 A.M.)
s₂: average speed during the lunch (interval from 12 P.M to 3 P.M.)
n: number of intervals