Given that:
[tex]R(p)=-4p^2+410p[/tex]To find the revenue received when p equals 91 dollars, substitute 91 for p into the formula of R(p).
[tex]\begin{gathered} R(91)=-4\cdot91^2+410\cdot91 \\ =4186 \end{gathered}[/tex]4186 dollars received from selling the shoes at a cost of 91 dollars.