The temperature fell by 3°F every hour over a 6-hour period. To find the overall change in temperature, multiply the rate of temperature change per hour by the total time:

$\text{Overall change} = 3^\circ F \times 6 \, \text{hours} = 18^\circ F$

Since the temperature is falling, the overall change is negative:

$\text{Overall change} = -18^\circ F$

So, the overall change in temperature during the 6-hour period was a decrease of 18°F.

Would you like more details or have any questions?

Here are 5 related questions to expand on this concept:

1. What would the overall change in temperature be if the period lasted 8 hours instead of 6 hours?
2. If the temperature started at 50°F, what would it be after the 6-hour period?
3. If the temperature fell by 5°F every hour for 4 hours, what would the total change in temperature be?
4. How much would the temperature change if it fell by 2°F every 30 minutes over a 6-hour period?
5. What if the temperature rose by 2°F every hour for 6 hours? What would the overall change be?

Tip: Always keep track of whether a value is increasing or decreasing, as it affects whether the overall change is positive or negative.