The per capita personal income (in dollars per year) in the United States for selected years from 1960 and projected to 2018 can be modeled by I(t)=13.93t2+136.8t+1971 Where t is the number of years past 1960 (Source: U.S. Bureau of Labor Statistics). Use n=10 equal subdivisions with right-hand endpoints to approximate the area under the graph of I(t) between t=50 and t=55. What does this area represent?