Answer:
-5°F in 1 hour
Explanation:
We Know
At 6:00 p.m., the temperature outside was 60°F.
10:00 p.m. it had fallen to 40°F
What was the average rate of change of the temperature that evening?
The degree decreased by 20°F in 4 hours.
Rate of change = -20/4 = -5°F
So, the rate of change is -5°F