Explanation
An exponential model for population growth has the following model:
[tex]P=P_0(1+r)^t[/tex]Therefore; since the town has a population growth that doubles in 10 years
[tex]\begin{gathered} 2P_0=P_0(1+r)^{10} \\ 2=(1+r)^{10} \\ \sqrt[10]{2}=\sqrt[10]{(1+r)^{10}} \\ 1.07177=1+r \end{gathered}[/tex]In 12 years, we will have
[tex]\begin{gathered} P=3100\left(1.07177\right)^{\left\{12\right\}} \\ P=7121.65370 \\ P=7122 \end{gathered}[/tex]Answer: 7122