In 1990, a certain country's population was 71, 839, 603 and it's area was 2,830,762 square miles. In 1980, the country's population was 283, 897, 819 and it's area was 3,512, 772 square miles. Compute the population densities of both years.

population density is people/mi^2

just do the divisions: population/area
and then compare.

Population density = population/area

for the first case:
densitity in 1990 = 71,839,603/2,830,762 = ..... people/square mile
I assume you have a calculator

repeat the same steps for 1980

btw, this question makes very little sense.
How can the area of a country increase? Was there a war?
How did the country lose 212 million people in 10 years????

To compute the population density, we need to divide the population of a country by its area.

For the year 1990:
Population = 71,839,603
Area = 2,830,762 square miles

Population Density = Population / Area
Population Density = 71,839,603 / 2,830,762
Population Density ≈ 25.38 people per square mile

For the year 1980:
Population = 283,897,819
Area = 3,512,772 square miles

Population Density = Population / Area
Population Density = 283,897,819 / 3,512,772
Population Density ≈ 80.80 people per square mile

So, the population density in 1990 was approximately 25.38 people per square mile, while in 1980 it was approximately 80.80 people per square mile.