γ = Cp/Cv
ε = W/Qh
PiVi^γ = PfVf^γ
The Attempt at a Solution
I know I have to find the gamma firstly in order to determine what type of gas is present here. And to do that I have to pick one of the adiabatic processes. I chose to do AD. But I am literally lost at how to set this up because we aren't really given values and reading graphs is not one of my strong suits in physics.
Note - The green in picture means "Correct". I just input 1 for the gas and .25 for the efficiency off guessing.