Answer :
the formula is
[tex]y=8.50+0.45\left(x-3\right)[/tex]For $10,
[tex]\begin{gathered} 10=8.5+0.45(x-3) \\ 10-8.5=0.45x-1.35 \\ 1.5+1.35=.45x \\ \frac{2.85}{0.45}=x \\ x=6.3 \end{gathered}[/tex]So when, x=6.3, y=$10,
the formula is
[tex]y=8.50+0.45\left(x-3\right)[/tex]For $10,
[tex]\begin{gathered} 10=8.5+0.45(x-3) \\ 10-8.5=0.45x-1.35 \\ 1.5+1.35=.45x \\ \frac{2.85}{0.45}=x \\ x=6.3 \end{gathered}[/tex]So when, x=6.3, y=$10,