The table below lists the U.S. unemployment rate in October for selected years.
Year U.S. Unemployment Rate in October
2002 ...................... 5.7%
2004 ......................... 5.5
2005 ......................... 5.0
2008 ......................... 6.6
2010 ........................ 9.7
a) Use a graphing calculator to fit a quadratic function f 1x2 = ax2 + bx + c to the data, where x is the number of years since 2002.
b) Use the function found in part (a) to estimate the unemployment rate in 2003, in 2007, and in 2009.