4.12 By studying, Will can produce a higher grade, GW, on an upcoming economics exam. His production function depends on the number of hours he studies marginal analysis problems, A, and the number of hours he studies supply and demand problems, R. Specifically, GW = 2.5A0.36R0.64. The grade production function of his roommate David is GD = 2.5A0.25R0.75.

a. What is Will’s marginal productivity from studying supply and demand problems? What is David’s?

b. What is Will’s marginal rate of technical substitution between studying the two types of problems?

What is David’s?

c. Is it possible that Will and David have different marginal productivity functions but the same marginal rate of technical substitution functions?

Explain. M L-9687