Answer to Question 1
Answer: Density is defined as the number of people occupying an area of land. This concept can be measured in three distinct ways: arithmetic, physiological and agricultural densities. Each of these measures of density helps describe the distribution of people in comparison to available resources.
Of the three measures of density, the one most frequently used by Geographers is the Arithmetic Density. This is the total number of people divided by total land area. Because of this, this is a basic, quickest and most used measure to compare conditions in different countries.
Physiological Density is a more meaningful population measure. Here, we look at the number of people per area of arable land, which is land suited for agriculture. Generally, the higher the physiological density, the greater the pressure that people may place on the land to produce enough food. It also provides insights into the relationship between the size of a population and the availability of resources in a region.
The third meaningful measure of density is Agricultural Density. This is the ratio of the number of farmers to the amount of arable land. Two countries can have similar physiological densities, but they may produce significantly different amounts of food because of different economic conditions. This measure helps account for economic differences, such as large-scale mechanized farming ( by few farmers on large farms) in one country versus small-scale, labor intensive farming ( by several farmers on small farms) in another country.
Answer to Question 2
Answer: TRUE
The mark-recapture technique is often used to estimate population size.
The Median Age of the U.S. Population
World Population Growth
Population: Historic Patterns
Population Density versus Economic Growth
Distribution Patterns and Population Size Estimates (Bio 30)