Let's break down the temperature changes step by step.
- The initial temperature is 76°F.
- The temperature drops by 9°F:
\( 76°F - 9°F = 67°F \) - The temperature then rises by 13°F:
\( 67°F + 13°F = 80°F \)
Now, we need to find out how much the temperature needs to change from 80°F to return to the initial temperature of 76°F:
To return to 76°F from 80°F:
\( 80°F - 76°F = 4°F \)
Since 80°F is higher than 76°F, the temperature needs to fall by 4°F.
Thus, the answer is: Fall 4°F.