Prior to beginning work on this assignment, review Chapters 9, 10 and 11 from your textbook, Principles of microeconomics and How to Calculate Total Cost, Marginal Cost, Average Variable Cost, and ATCLinks to an external site.. A firm operating in perfect competition has no influence over market price. It can sell any amount at the market-clearing price. The only one major decision to make then is about what quantity should be produced. When it decides the quantity to produce, then this quantityalong with the prices prevailing in the market for output and inputswill determine the firm's total revenue, total costs, and ultimately, level of profits