To find the location of the basement woodshop, we need to calculate the total change in height from Arthur's room to the basement.
Arthur is currently at a height of 24.3 feet above ground level, and he descends 39.9 feet to the basement. We can determine the height of the basement relative to ground level with the following calculation:
- Start at Arthur's height: 24.3 feet
- Subtract the descend distance of 39.9 feet:
\[ 24.3 \text{ feet} - 39.9 \text{ feet} = -15.6 \text{ feet} \]
Thus, the basement woodshop is at -15.6 feet relative to ground level.
The number that best describes the location of the basement woodshop is:
−15.6 feet (negative 15.6 feet).