For a perfectly competitive firm, marginal revenue equals what?

1. Because a price-taking firm sells every unit at the same market price, each additional unit sold adds exactly that price to revenue. 2. That means marginal revenue equals price for a perfectly competitive firm. 3. Average total cost is a cost concept, not a revenue concept, so it does not equal marginal revenue. 4. Marginal revenue equals marginal cost only at the specific profit-maximizing quantity, not at every quantity, so 'always' is too strong a claim. _Source: OpenStax Principles of Microeconomics for AP Courses (CC BY 4.0), Ch 8 "Perfect Competition", section 8.2 | How Perfectly Competitive Firms Make Output Decisions_