How is population density determined?

Hint: Population density refers to number of people per unit area (per square kilometre or per square mile. Lesser the number of people per unit area lesser is the population density and more the number of people per unit area more is the population density.

Complete answer:
Population density is the number of people living per unit area of a land. It is expressed in per square kilometre or per square mile.
The formula for calculating population density is-
Population density ${\text{ = }}\dfrac{{{\text{Number of people}}}}{{{\text{Land area per square km}}}}$
So population density determines this formula by substituting the values into it. If the value comes in fraction convert it either to decimal or a whole number. The decimal must be rounded off to its nearest whole number. Whatever number/solution obtained gives the number of people per unit area of that particular place which is the population density.
If the number of people in a unit area is small then the population density is less and if the number of people in the unit area is large then the population density is more.
For e.g. if we want to calculate the population density of a town which is 20 square km and has 1500 people then by substituting the values in the formula we get the population density as
Population density =$\dfrac{{1500}}{{20}} = 75$ i.e. $75$ people per square kilometre

Note: There are numerous factors which affect population density: Natural and human factors
Physical/natural factors include- relief (topography of a place), climate and natural resources. Areas having moderate climatic conditions and abundant natural resources tend to inhabit a maximum number of people and have greater population density.Human factors involve- political, social and economic factors.
Places having a stable government or administration, having proper living conditions and people willing to live in harmony are more preferable to live in.