#### Answer

$a.\displaystyle \qquad\frac{4}{5}$
$ b.\qquad$The graph also shows the fraction to be $\displaystyle \frac{4}{5}$.
(The model coincides with the data for 2010)
$c.\displaystyle \qquad\frac{49}{50}$

#### Work Step by Step

$a.$
Substitute 10 for x (2010 was 10 years after 2000):
$I=\displaystyle \frac{3}{100}\cdot 10+\frac{1}{2}=$... reduce the product by 10
$=\displaystyle \frac{3}{10}+\frac{1}{2}\qquad$... LCD is 10
$=\displaystyle \frac{3}{10}+\frac{1\times 5}{2\times 5}$
$=\displaystyle \frac{3+5}{10}$
$=\displaystyle \frac{8}{10}\qquad $... reduce by 2
$=\displaystyle \frac{4}{5}$
$b.$
The graph also shows the fraction to be $\displaystyle \frac{4}{5}$.
(The model coincides with the data for 2010)
$c.$
Substitute $16$ for x ($2016$ was $16$ years after 2000):
$I=\displaystyle \frac{3}{100}\cdot 16+\frac{1}{2}=$... reduce the product by $2$
$=\displaystyle \frac{3\cdot 8}{50} +\frac{1}{2}$
$=\displaystyle \frac{24}{50} +\frac{1}{2}\qquad$... LCD is $50$
$=\displaystyle \frac{24}{50}+\frac{1\times 25}{2\times 25}$
$=\displaystyle \frac{24+25}{50}$
$=\displaystyle \frac{49}{50}$