Answer:
52.5 ft
Step-by-step explanation:
Let:
x = tree height of the tree with a 17.5 ft shadow
Ratio of tree height to shadow length:
15 : 5 → [tex]\frac{15}{5}[/tex]
x : 17.5 → [tex]\frac{x}{17.5}[/tex]
The ratios are the same so they can be used to construct an equation, which can be solved to find x:
[tex]\frac{x}{17.5} = \frac{15}{5} \\\\ x = 3(17.5) \\\\ x = 52.5[/tex]
