monopolistic competitor wishing to maximize profit will select a quantity where marginal cost equals demand. marginal cost equals average cost. marginal revenue equals marginal cost. marginal revenue equals average cost. if a firm is producing a quantity where marginal revenue exceeds marginal costs, the firm should existing levels of production in order to . expand ; increase profitability decrease ; increase total revenue expand ; decrease total costs decrease ; increase profitability if a firm is producing a quantity where marginal cost exceeds marginal revenue, the firm should existing levels of production in order to . decrease ; increase total revenue decrease ; increase profitability expand ; increase profitability expand ; decrease total costs