Solution
If y is directly proportional to x2 and y = 487 when x = 18, find y if x = 6.
[tex]\begin{gathered} y\infty x^2 \\ y=kx^2 \\ k=\frac{y}{x^2ControlControl} \end{gathered}[/tex]when y = 487 and x² = 18
[tex]\begin{gathered} 487=k(18)^2 \\ k=\frac{487}{18^2} \\ k=\frac{487}{324} \\ k=1.507 \end{gathered}[/tex]Find y when x = 6
[tex]\begin{gathered} y=kx^2 \\ y=1.507x^2 \\ y=1.507(6)^2 \\ y=1.507(36) \\ y=54.11\text{ \lparen nearest hundredth\rparen} \end{gathered}[/tex]Therefore the correct answer is 54.11