Classy Cruiseline offers nightly dinner cruises departing from several cities on the eastem coast of the United States including Charleston, Baltimore, and Alexandria. Dinner cruise tickets sell for $80 per passenger. Classy Cruiseline's variable cost of providing the dinner is $40 per passenger, and the fixed cost of operating the vessels (depreciation, salaries, docking fees, and other expenses) is S360,000 per month. The company's relevant range extends to 19,000 monthly passengers. If Classy Cruiseline sells an additional 400 tickets, by what amount will its operating income increase (or operating loss decrease)? First, identify the formula, then compute the operating income increase (or operating loss decrease) - Operating