## Thinking Mathematically (6th Edition)

a. $38\%$ b. Between 2008 and 2009. c. 2003
a. The point on the axis representing the percentage in 2001 looks to be a bit after the middle between $35\%$ and $40\%$, so we can estimate that it's $\approx 38\%$. b. To see between which two years the percentage decreased at the greatest rate, we don't need to estimate the value of every point and calculate the difference between them. We simply need to see between which two years the slope is the steepest and heading downwards. We can clearly see that the steepest slope in the graph is between the years 2008 and 2009; therefore, the percentage decreased the most between 2008 and 2009. c. Looking at the points on the graph for each year and their distance from the dotted line for $30\%$, we can see that the only point that could be at $32\%$ is 2003.