I can't come to terms with the solution given by the book for Ch33 Q3. Why wouldn't you use the below formula from p287 of the HB? image This method gives a much different answer that seems more logical than the answer given by the book (822degF vs 400degF). Section A of the composite wall is the thinnest section and has the second lowest thermal conductivity out of the 3 sections - therefore, you wouldn't expect temperature to drop by more than half through this section. Am I missing something? And if I am indeed wrong, why doesn't the method on p287 of the handbook work here