William W. answered 09/14/20
Top Algebra Tutor
The temperature change is 65 - 43 or 22°F
Since the temperature drops 3.7°F for each 1000 feet, we just need to know how many "3.7's" there are in 22. We find that out by dividing.
So 22/3.7 = 5.946
That means the altitude must be at 5.946•1000 ft or 5,946 feet above the altitude it took off at.
It might be easier to think about if you made a simple version of this problem up. What if there temperature dropped by 15°F and what if the temperature changes by 5°F for each 1000 feet. Can you see that the altitude must be 3000 feet (the temp drops 5°F after 1000 ft, then another 5°F in the second 1000 ft and then another 5°F in the third 1000 ft)? So we take the temperature change (15°F) divided by the rate the temperature changes (5°F/1000ft) then multiply by 1000 (15/5 = 3 and 3•1000 = 3000 ft. We do the same with the real problem: 22°F/3.7°F = 5.946 and 5.946•1000 = 5946 ft