The numbers of AP tests administered are shown in Table 9 for various years.
Table 9
Numbers of APTests Administered
Number of AP Tests
YearAdministered (millions)
1980 ………………………..0.2
1985 ………………………..0.3
1990 ………………………..0.5
1995 ………………………..0.9
2000 ………………………..1.3
2005 ………………………..2.1
2010 ………………………..3.3
2014 ………………………..4.2
Let y be the number (in millions) of AP tests administered in the year that is x years since 1980.
a. Construct a scatterplot.
b. Is there a linear association, a nonlinear association, or no association?
c. Use technology to graph the equation  = 0.2(1.096)x on the scatterplot. Does the model come close to the data points?
d. Estimate the number of AP tests administered in 2010. Find the residual. What does it mean in this situation?
e. Estimate the number of AP tests administered in 2014. Find the residual. What does it mean in this situation?