Political Science—Ideological Affiliation: For the past 40 years, The American Freshman ha...

Political Science—Ideological Affiliation: For the past 40 years, The American Freshman has tracked interests, affiliations, and trends of incoming college freshmen. From 1980 to 2010, the percentage of incoming freshmen who classifed their political orientation as liberal can be modeled by the function

 f(x) = 0.01x2 − 0.03x + 21.83 0 ≤ x ≤ 30

where x represents the number of years since 1980, and f(x) represents the percentage of freshmen who classify their political orientation as liberal. Approximate the instantaneous rate of change of f when x = 26 and interpret.