Short Answer: Question #3 The following gure depicts the marginal social cost, average (private) cost, and demand (marginal benet) curve for urban transit ridership. Cost per Trip ($) AC MC MB Ridership (# of Riders) 3.1 Explain why the average cost curve is downward sloping [3 points], and why the average cost curve is above the marginal cost curve at low transit ridership levels [1 point]. Reference the concept of \"Mohring economies\" in your answer. 3.2 Mark the competitive equilibrium point on the curve as point A. [2 points] 3.3 Mark the socially optimal equilibrium point on the curve as point B. [2 points] 3.4 Shade in the appropriate deadweight loss triangle. [2 points]