One day at 3:00 a.m., the temperature was
–13°F in Kodiak, Alaska. At 10:00 a.m., the temperature was 22°F. What was the average change in temperature per hour?
The temperature changed by 22°F - (-13°F) = 35°F in 7 hours (from 3:00 a.m. to 10:00 a.m.).
Therefore, the average change in temperature per hour was 35°F / 7 hours = 5°F per hour.