Answer:
-7°F/hour.
Step-by-step explanation:
If the total change is -28°F, and we know it took 4 hours, we just have to divide the total change by hours taken to get the change per hour.
So we do the following: [tex]\frac{-28F}{4} = -7F/h[/tex]
So the temperature changes (drops) by -7°F/hour.