A measurement of population per unit of area, usually

quoted by square mile or kilometer, relates to which

demographic?

For humans, population density is the number of people per unit of area, usually quoted per square kilometre or square mile. Population density is calculated for a county, city, country or the entire world.

Explanation:

Population density is expressed as the number of people per square mile of land area. The ideal population density is between 50-100 people per square km. For humans, population density is the number of people per unit of area, usually quoted per square kilometer or square mile. Population density is calculated for a county, city, country, or the entire world.