please show working

Determine the bending stress at point $p({}_p)$ in $\frac{N}{m}{m}^2$ for the cross section shown in Figure $5\mathrm{.}1$ a$,$ which is subjected to a bending moment, $M=-6\mathrm{.}45kNm.$ Identify whether it is

under compression or tension.

Given $D-288mm,t_f-72mm,$ location of centroid from $x-$axis $-165\mathrm{.}6mm$ and second moment of area with respect to its centroidal $x^{\text{'}}-$axis $(l_{x^{\text{'}}})-96\mathrm{.}97{10}^{6}m{m}^4.$

$($Note: Negative sign $"-"$ for compressive strength$)$