A state-wide density is a single average over everything inside the state. It does not tell you how crowded any one town or district is.
This lesson belongs to population distribution and density. You need the division from calculating density first.
What does an average hide?
It hides the unevenness. Two places with very different densities can sit inside one state and still produce a moderate average.
The skill is to ask, for every density figure: “Which area does this cover?” Then only make claims about that area.
Worked example: one state, three levels
State Z has 900 000 residents in 6 000 km². Town T has 120 000 residents in 40 km². Highland district H has 30 000 residents in 2 400 km².
- State Z: 900 000 ÷ 6 000 = 150 per km².
- Town T: 120 000 ÷ 40 = 3 000 per km².
- District H: 30 000 ÷ 2 400 = 12.5 per km².
Town T is twenty times denser than the state average. District H is far below it. The state figure describes neither place.
The mistake that costs marks
The common slip is to write “State Z is crowded everywhere, because its density is 150.” The figure does not support “everywhere”.
| Claim | Supported? | Why |
|---|---|---|
| State Z has 150 per km² overall. | Yes | This is what the figure says |
| Every district in State Z is crowded. | No | The average cannot show the spread |
| Town T is much denser than the state average. | Yes | 3 000 is far above 150 |
| District H is denser than Town T. | No | 12.5 is far below 3 000 |
A safe sentence names the area and the level: “Overall, State Z has a density of 150 per km², but Town T is far denser.”
Check yourself
State P has an average density of 80 per km², and State Q has 400 per km². State P has a district with 600 per km². State Q has a district with 35 per km².
Is this statement true: “Every district in State Q is denser than every district in State P”?
Answer
The statement is false. State Q’s district of 35 per km² is less dense than State P’s district of 600 per km².
The two averages say State Q is denser overall. They cannot say that each of its districts beats each of P’s districts.
What to study next
Shaded maps give district information, but the legend uses classes, not exact values. Continue with reading a choropleth legend. For a wider view, read reading a population graph without stereotyping people.
If you want a teacher to test your claim sentences, see online one-to-one Geography tuition.