Respuesta :
Answer:
8.7 feet
Step-by-step explanation:
Complete such table:
[tex]\begin{array}{ccc}&\text{Height}&\text{Shadow}\\ \\\text{John}&5\ ft\ 7\ in&9\ ft\ 8\ in\\ \\\text{Tree}&x&15\ ft\end{array}[/tex]
Convert all measures into inches:
[tex]5 \ ft\ 7 \ in=(5\cdot 12+7)\ in=67\ in\\ \\9 \ ft\ 8 \ in=(9\cdot 12+8)\ in=116\ in\\ \\15 \ ft=15\cdot 12\ in=180\ in[/tex]
Then the table will be
[tex]\begin{array}{ccc}&\text{Height}&\text{Shadow}\\ \\\text{John}&67\ in&116\ in\\ \\\text{Tree}&x&180\ in\end{array}[/tex]
Write a proportion:
[tex]\dfrac{67}{x}=\dfrac{116}{180}[/tex]
Cross multiply:
[tex]116x=180\cdot 67\\ \\116x=12,060\\ \\x=103\dfrac{28}{29}\ in[/tex]
Convert it into feet:
[tex]103\dfrac{28}{29}\ in=\left(8\cdot 12+7\dfrac{28}{29}\right)\ in=8\ ft\ 7\dfrac{28}{29}\ in\approx 8\ ft\ 8\ in=8\dfrac{8}{12}\ ft=8\dfrac{2}{3}\ ft\approx 8.7\ ft[/tex]