To find out how much the temperature needs to change to return to the initial temperature of 67 °F, we start by calculating the temperature after the changes.
- The initial temperature is 67 °F.
- The temperature drops by 6 °F: \[ 67 - 6 = 61 \text{ °F} \]
- Then the temperature rises by 10 °F: \[ 61 + 10 = 71 \text{ °F} \]
Now, the current temperature is 71 °F. To return to the initial temperature of 67 °F, we need to calculate the difference: \[ 71 - 67 = 4 \text{ °F} \]
Therefore, the temperature needs to fall by 4 °F to return to the initial temperature of 67 °F.