Answer
U.S diversity index(D) in 2010 (30 years after 1980)= 55
Both the bar graph and formula give the same results
Work Step by Step
U.S diversity index(D) $x$ years after 1980 = 0.005$x^{2}$ + 0.55$x$ + 34
U.S diversity index(D) in 2010 (30 years after 1980) = 0.005$\times30^{2}$ + 0.55$\times30$ + 34
= 0.05$\times$900 + 0.55$\times30$ + 34
= 4.5 + 16.5 +34 = 55
Both the bar graph and formula give the same results
