The coffee travel mug industry is perfectly competitive, where firms sell each travel mug for $15.60. There are 2,300 identical firms in the industry. For the average firm: their marginal revenue for the last travel mug sold is equal to $ ______. Their average revenue is equal to $ _________ . Their marginal cost for the last travel mug produced is qual to $ _________. The profit earned on the last travel mug sold is equal to $ _________