There's a lot of numbers here, which can tend to obscure our view of the important parts of the problem, and how to solve it.
The important parts of the problem are: Mass = 83.6 kg, and Force = 1017 N.
The way to solve it is: F = m a
That's Newton's 2nd law. Divide each side by 'm' and it says a = F/m .
acceleration = (force) / (mass)
acceleration = (1017 N) / (83.6 kg)
acceleration = 12.2 m/s²
If we say that UP is the POSITIVE direction, then the diver's velocity is negative (down), the force of air resistance is positive (up), and the acceleration is positive (up).