Identify the key curves on the graph: Demand (D), Marginal Revenue (MR), Marginal Cost (MC), and Average Total Cost (ATC).
Recall that a monopolist maximizes profit by producing the quantity where Marginal Revenue (MR) equals Marginal Cost (MC). Locate this intersection point on the graph.
At the profit-maximizing quantity, draw a vertical line up to the Demand curve to determine the price the monopolist will charge.
Note that at this quantity, the price (from the Demand curve) is greater than the Marginal Cost (MC), which is a characteristic of monopoly pricing.
Understand that the difference between price and marginal cost indicates that price exceeds marginal cost, confirming the statement that at the monopolist's profit-maximizing output, price exceeds marginal cost.