
$\Sigma M_A = 0$
$N_B(2x) = 424x + f_B(2x)$
$2N_B = 424 + 2f_B$
$2N_B = 424 + 2(0.268N_B)$
$1.464N_B = 424$
$N_B = 289.62 \, \text{ N}$
$f_B = 0.268(289.62)$
$f_B = 77.62 \, \text{ N}$
$\Sigma F_V = 0$
$N_A = f_B + 200 + 424$
$N_A = 77.62 + 200 + 424$
$N_A = 701.62 \, \text{ N}$
$f_A = 0.20(701.62)$
$f_A = 140.32 \, \text{ N}$
$\Sigma F_H = 0$
$P = f_A + N_B$
$P = 140.32 + 289.62$
$P = 429.94 \, \text{ N}$ answer