Answer
$ a.\quad 25.1$ million
$ b.\quad $ in $2015$
Work Step by Step
$ a.$
In the year 2010, t is 0.
Substitute 0 for t in the formula and calculate.
$ A=25.1e^{0}$ = $25.1$ million.
$ b.$
Solve for t when $ A=28.$
$ 28=25.1 e^{0.0187t}\quad $ ... $/\div 25.1$
$\displaystyle \frac{28}{25.1}=e^{0.0187t}\quad $ ... $/\ln(...)$
$\displaystyle \ln(\frac{28}{25.1})=0.0187t \quad $ ... $/\div 0.0187$
$ t=\displaystyle \frac{\ln(\frac{28}{25.1})}{0.0187}\approx 5.847$ (years after 2010)
The population will reach $28$ million in $2015$.
