A stone wall in an old house can be modeled as a homogenous plane wall 225 mm thick. Estimate the heat loss through the wall per unit area if the convective heat transfer coefficients in the inside and outside are 10 and 65 W/m2-K, respectively, and the inside and outside air temperatures are 20oC and 0oC, respectively. The thermal conductivity of the stone is 2.15 W/m- K.