Use the graph to answer the question. Assume the price of capital is $6 and the price of labor is $3. To produce Q1 the firm uses 13 units of labor and 2 units of capital. If Q1 on the graph was 12 and it the TC of producing 13 units was $90, the value of Z on the graph is: $/unit TC = FC + VC MC TC=TC = PK * K + PL * L ATC = AFC + AVC TC FC VC TC PX * K 0 Q MC= ATC AQ ATC X Y Z Quantity Q1 (firm)