Using the formula for population density, it is found that the approximate area of Puerto Rico is of 3980 square miles.
It is given by the number of habitants divided by the area, that is:
[tex]D = \frac{H}{A}[/tex]
In this problem, we have that:
Hence:
[tex]D = \frac{H}{A}[/tex]
[tex]10^3 = \frac{3.98 \times 10^6}{A}[/tex]
[tex]A = \frac{3.98 \times 10^6}{10^3}[/tex]
A = 3980.
The approximate area of Puerto Rico is of 3980 square miles.
More can be learned about population density at https://brainly.com/question/26148357