Amtrak S Annual Passenger Revenue for the Years 1985-1995 Is

Short Answer

Amtrak s annual passenger revenue for the years 1985-1995 is modeled approximately by the formula where R is the annual revenue in millions of dollars and x is the number of years since January 1, 1980 (Association of American Railroads, Washington, DC, Railroad Facts, Statistics of Railroads of Class 1, annual). In what years was the passenger revenue $722 million?