Standardized Choropleth Map

This is an example of a Standardized Choropleth Map because it measures the population in the United States (Census 2000) per square mile. The shades are purple are also used to illustrate the population; the darker shades representing a higher population per square foot. According to the map, New Jersey has one of the most populated states with the population showing +1000 per square mile.

http://upload.wikimedia.org/wikipedia/commons/thumb/7/78/USA_states_population_density_map.PNG/800px-USA_states_population_density_map.PNG