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