Chapter 6 - Applications of the Integral - 6.2 Setting Up Integrals: Volume, Density, Average Value - Exercises - Page 298: 29

$4423.59 \ \ thousand = 4.4 \ \ million.$

The total population is given as follows $$ 2 \pi \int_{0}^{10} r \rho(r) d r=4 \pi \int_{0}^{10} 2 r\left(1+r^{2}\right)^{1 / 3} d r\\=\left.3 \pi\left(1+r^{2}\right)^{4 / 3}\right|_{0} ^{10}=4423.59 \ \ thousand\\ = 4.4 \ \ million. $$