A beam is subjected to $M_B=12$kip$-ft$ bending moments. The cross$-$sectional dimensions of the beam are shown in figure. The distance of the centroid of the section to the top of the beam is $y=7\mathrm{.}49$ in$.$ and the moment of inertia about the horizontal axis is $I_z=214\mathrm{.}08i{n}^4.$

$]=10in.,b=18in.,t=[0\mathrm{.}5in.$

What is the bending stress at point $H?$

$-13040$

$-7200$

$-12250$

$-5040$ psi