A rigid insulated tank is initially evacuated. It is connected through a valve to a supply line that carries air at a constant pressure and temperature of $\text{250 kPa}$ and $\text{400 K}$ respectively. Now the valve is opened and air is allowed to flow into the tank until the pressure inside the tank reaches to $\text{250 kPa}$ at which point the valve is closed. Assume that the air behaves as a perfect gas with constant properties $\left ( c_{p}=1.005\text{ kJ/kg.K}, \: c_{v}=0.718 \text{ kJ/kg.K}, R=0.287 \text{ kJ/kg.K}\right )$. Final temperature of the air inside the tank is _______ $\text{K}$ ($\textit{round off to one decimal place}$).