The average total cost is 90 (ATC = 90) and the average variable cost is 60 (AVC = 60).
a. What is the total cost (TC) of producing these 50 units of output?
b. How much is the total fixed cost (TFC)?
If the ATC of producing 60 units is 100,
c. What is the total cost (TC) of producing these 60 units of output (Q=60)?
d. Use your answers to parts a and c to calculate the marginal cost (MC) of producing one additional unit of output between Q = 50 and Q = 60?