Question

About 635,000 people live in a 5-mile radius of a city's town hall. Find the population densityin people per square mile.You need to calculate the area of a circle with a radius of 5 to use as the area of the land!Use the n button on your calculator; do not use 3.14.Round your answer to the nearest hundredth.

Answer 1

The area of a circle with radius r is given by::

$A=\pi r^2$

For r = 5 miles, we have:

$A\approx3.14\cdot5=15.7\text{ miles}^2$

Considering that P 635,000 people lives in this area, the population density d is given by:

$d=\frac{P}{A}=\frac{635000}{15.7}=\approx40,445.86\text{ }\frac{people}{mile^2}$