In an ideal Rankine cycle, the enthalpy of steam at the inlet of the turbine is 3000 kJ/kg and that at the outlet of the pump it is 200 kJ/kg. The entropy of steam at the inlet to boiler is 0.615 kJ/kg-K and that at the inlet to turbine is 6.23 kJ/kg-K. The temperature of heat addition (mean) for the cycle is