Answer:
3 °F/h
Step-by-step explanation:
The rate per hour of temperature change = change in temperature per measurement/change in time per measurement.
Now, the change in temperature per measurement is constant = 3/4 °F and the change in time per measurement is constant = 15 minutes = 15/60 h = 1/4 h.
So, rate per hour of temperature change = change in temperature per measurement/change in time per measurement
= 3/4 °F ÷ 1/4 h
= 3/4 °F × 4/h
= 3 °F/h
So, the rate per hour of temperature change is 3 °F/h