Methane at 9.3 MPa, 300 K enters the turbine operating at steady state at a mass flow

Question:

Methane at 9.3 MPa, 300 K enters the turbine operating at steady state at a mass flow rate (m) of 1 kg/s, expands adiabatically through a 6:1 pressure ratio, and exits at 225 K. KE and PE effects are negligible. Using the RG model (L-K charts), determine (a) the power developed (Wext) and (b) the entropy produced (Sgen). (c) What-if Scenario: What would the power developed be if PG model were used?