Answer:
Unit rate of change = -4.2°F/hour
Step-by-step explanation:
Assuming a constant rate of change, a relationship between the change of temperature as a function of time (in hours) can be described as follows:
There is a temperature drop from 12pm to 5pm, which explains the rate of change being negative. This rate means that at every hour that goes by, the temperature drops by 4.2 degrees.