Country X has five states, ABCD and E with population statistics and land area as stated in the table below state Total population(million) Total land Area ...

(a)(i) Total population

\(5.4 + 4.2 + 6.5 + 3.2 + 7.4 = 26.7\) million, i.e. 26,700,000 people.

(a)(ii) Total land area

\(120{,}000 + 85{,}000 + 135{,}000 + 98{,}000 + 140{,}000 = 578{,}000\ \text{km}^2\).

(a)(iii) Population density

\[\text{Density} = \frac{\text{total population}}{\text{total land area}} = \frac{26{,}700{,}000}{578{,}000} \approx 46.2\ \text{persons per km}^2.\] The population density of Country X is about 46 persons per km².

(b) Four factors responsible for the distribution of world population

1. Climate: areas with moderate, favourable climates attract dense settlement, while very hot deserts, very cold polar lands and wet equatorial forests repel people.
2. Relief and soils: lowland plains and river valleys with fertile soils support large populations, whereas rugged mountains and infertile land are sparsely peopled.
3. Water supply and drainage: reliable fresh water (rivers, lakes, wells) draws people, so populations cluster along rivers and coasts and avoid arid interiors.
4. Economic and industrial development: areas with mining, industry, commerce and good transport offer jobs and services, pulling in large populations (urbanisation), while remote areas remain thinly settled.

(c) Three factors that cause increase in world population

1. A high birth rate resulting from early marriage, large-family preferences and low use of family planning.
2. A falling death rate brought about by better medical care, immunisation, improved sanitation and food supply.
3. Improved standards of living and nutrition, together with in-migration into an area, which raise life expectancy and add to numbers.