Answer:
P_up-P_low = 4518 Pa
Step-by-step explanation:
The pressure definition is
P = F / A
We cleared the force
F = P A
Let's write Newton's second law
∑ F = F_up - F_ low
∑F = P_ up A - P_low A
As the plane is in equilibrium (going at constant speed) the sum of force is equal to zero
A (P_up -P_low) - W = 0
P_up - P_low = W / A
P_up-P_low = 77000 9.8 / 167
P_up-P_low = 4518 Pa
assumptions that the area in the two parts of the wing is equal