Given the following information about a competitive firm's costs, calculate marginali cost and then answer three questions.. Instructions: Enter your responses as a whole number. If you are entering any negative numbers be sure to include a negative sign (-) in front of those numbers. Output (Units) Total Cost ww 10 1 12 13 + 15 6 11 14 16 17 18 19 $50 52 56 62 70 80 92 106 122 140 units Marginal Cost a. If the prevailing market price is $4 per unit, how much should the firm produce? b. How much profit will it earn at that output rate? c. If the firm decreases output by 2 units, the firm will make profit.