Question

About 79,000 people live in a circular region with a population density of about 513 people per square mile. Find the radius of the region. Round your answer to the nearest whole number.

Answer 1

To solve this problem, let us first assign some variables. Let us say that:

d = represents the population density of the circular region (in units of 513 people per square mile)

p = represents the population of the circular region (in units of people)

r = is the radius of the circular region

 

Now we can see that if we divide p by d, we can get a value which has a units of square mile. Thus the area of the region, hence:

Area = 79,000 people / (513 people per square mile)

Area = 154 square mile

 

The area of a circle has the formula:

Area = π r^2

Therefore calculating for r:

154 square mile = π r^2

r = 7 miles            (ANSWER)