A $14-$ft$-$long simply supported timber beam carries a $P=17\mathrm{.}0-$kip concentrated load at midspan as shown. The cross$-$sectional dimensions of the timber are also shown. At section $a-$a$,$ determine the magnitude of the shear stress in the beam at point $H.$

$76\mathrm{.}5$ psi

$114\mathrm{.}8$ psi

$90\mathrm{.}7$ psi

$58\mathrm{.}3$ psi

$85\mathrm{.}1$ psi