Answer:
The rate is -3°F per hour.
Explanation:
The rate of change of the temperature per hour, will be equal to the quotient between the total change in temperature and the time it took for the change.
We know that the initial temperature is 0°F
The final temperature is -(6 + 3/5)°F
Then the change in the temperature will be:
Final temperature - initial temperature = -(6 + 3/5)°F - 0°F = -(6 + 3/5)°F
We know that this change took a total of (2 + 1/5) hours, then we can conclude that the rate will be:
Rate = -(6 + 3/5)°F/(2 + 1/5) hs = -(30/5 + 3/5)°F/(10/5 + 1/5) hs
= -(33/5)°F/(11/5)hs = -(33/11) °F/hs = -3 °F/hs
This means that the rate of change is -3°F per hour, so the temperature decreases 3 °F for each hour that passes.