Excel Cruiseline offers nightly dinner cruises off the coast of Nanaimo and Victoria. Dinner cruise tickets sell for $60 per passenger. Excel Cruiseline's variable cost of providing the dinner is $30 per passenger, and the fixed cost of operating the vessels (depreciation, salaries, docking fees, and other expenses) is $225,000 per month. The company's relevant range extends to 20,000 monthly passengers. If Excel Cruiseline sells an additional 300 tickets, by what amount will its operating income increase (or operating loss decrease)? First, identify the formula, and then calculate the operating income increase (operating loss decrease). = Operating income increase (loss decrease) X