A 0.2 m thick infinite black plate having a thermal conductivity of 3.96 W/m-K is exposed to two infinite black surfaces at 300 K and 400 K as shown in the figure. At steady state, the surface temperature of the plate facing the cold side is 350 K. The value of Stefan-Boltzmann constant,  is  Assuming 1-D heat conduction, the magnitude of heat flux through the plate (in w/m²) is __________ (correct to two decimal places).