One end of a long rod is inserted into a furnace, while the other end projects into outside air. Under steady-state condition, the temperatures of the rod at 50 mm and 125mm from the furnace wall...

One end of a long rod is inserted into a furnace, while the other end projects into outside air. Under steady-state condition, the temperatures of the rod at 50 mm and 125mm from the furnace wall measured with the help of thermocouples indicate 125°C and 88.5°C when the ambient temperature is 20°C. Find the temperature of the rod at the furnace wall.