Repeat Worked-Out Problem 19.1, but assume instead that Joe's marginal cost is $25 per cubic yard instead of $40 per cubic yard; Rebecca's remains at $40. What are the equilibrium quantities, price, and profits in this market? How do they compare to the market in which both firms face a marginal cost of $40? Graph the best responses in the two cases, showing the Nash equilibrium in each. Is the total output produced at the lowest possible cost?