Figure 6.4 shows the short-run position of Hals Electronics, a typical firm selling radios in a monopolistically competitive market. Hals profit-maximizing output, price, and total revenue will be ________, _______, and ______. At the profit-maximizing output, Hals average total cost and total cost will be ______ and ______. Hal will earn an economic profit of ______. Attracted by short-run economic profits, suppose that firms enter this industry. In the long run, what will be the effect on Hals demand curve, marginal revenue curve, and economic profits?