Consider the following data for a firm operating in perfect competition.
| Quantity | Total Revenue | Total Cost |
| 21 | $210 | $138 |
| 22 | $220 | $145 |
| 23 | $230 | $154 |
| 24 | $240 | $165 |
The firm’s profit-maximizing output (in units) is most likely:
Under perfect competition, economic profits are maximized where marginal revenue equals marginal cost; in this case where marginal cost crosses$10 per unit. Profits are maximized at 23 units of production.