Answer
The total force that the seat exerts on the pilot is 870 N.
Work Step by Step
Let $F_p$ be the total force that the seat exerts on the pilot.
$\sum F_x = ma ~cos(\theta)$
$F_{px} = ma ~cos(\theta) = (75 ~kg)(3.8 ~m/s^2) ~cos(18^{\circ})$
$F_{px} = 271~N$
$\sum F_y = ma ~sin(\theta)$
$F_{py} - mg = ma ~sin(\theta)$
$F_{py} = m(g+a ~sin(\theta))$
$F_{py} = (75 ~kg)(9.80 ~m/s^2 + 3.8 ~m/s^2 \cdot sin(18^{\circ}))$
$F_{py} = 823 ~N$
Now, we find $F_p$:
$F_p = \sqrt{F_{px}^2 + F_{py}^2} = \sqrt{(271 ~N)^2+(823 ~N)^2}$
$F_p = 870 ~N$
The total force that the seat exerts on the pilot is 870 N.
