Cruiseline offers nightly dinner cruises departing from several cities on the East Coast of the United States including Charleston, Baltimore, and Alexandria. Dinner cruise tickets sell for

$60

per passenger.

Great

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

$270,000

per month. The company's relevant range extends to

19,000

monthly passengers.

If

Great

Cruiseline sells an additional

400

tickets, by what amount will its operating income increase (or operating loss decrease)?