The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 41.0724\\[1 em]x_2 &= 307.1952\\[1 em]x_3 &= 821.7324 \end{aligned} $$Polynomial $ -x^3+1170x^2-298800x+10368000 $ has no rational roots that can be found using Rational Root Test, so the roots were found using qubic formulas.