The price charged by a monopolistic competitor for each unit of a good is $7. If it produces 5,000 units of the good at a total cost of $25,000, what is his profit?

An economist conducts a "natural experiment" by

A) choosing two groups of people — a control group and a test group — and providing special treatment for the test group. B) using animal behavior to make inferences about human behavior. C) using his or her own intuition to surmise what people will do in a given situation. D) polling other economists to see if they believe a theory. E) taking real-world data as it is given, and using it to test a theory.

Suppose Alice sells a good for $60 on eBay. If the producer surplus from the sale is $25, Alice's cost of the good must have been:

a. $35 b. $25. c. $60 d. $85.