7/31/2019 Actividades Tema 1.Population Pyramid

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Mara CaballeroI.E.S. FERNANDO III EL SANTO / PROYECTO BILINGE A.N.L.: MATHS 1

MATHS

Lesson 1. Population pyramid

A population pyramid, also called age-sex pyramid and age structure diagram, is a graphicalillustration that shows the distribution of various age groups in a human population (typically thatof a country or region of the world), which normally forms the shape of a pyramid.

It typically consists of two back-to-back bar graphs, with the population on the X-axis and age on

the Y-axis, one showing the number of males and one showing females in a particular populationin five-year age groups (also called cohorts). Males are conventionally shown on the left andfemales on the right, and they may be measured by raw number or as a percentage of the total

population.

A great deal of information about the population broken down by age and sex can be read from a population pyramid, and this can show other aspects of the population. A population pyramid alsotells how many people of each age range live in the area. There tends to be more females thanmales in the older age groups, due to females' longer life expectancy.

http://upload.wikimedia.org/wikipedia/commons/c/c0/Population_pyramid_1_%28triangle%29.PNG

This distribution is named for the pyramidal shape of its graph.

7/31/2019 Actividades Tema 1.Population Pyramid

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Mara CaballeroI.E.S. FERNANDO III EL SANTO / PROYECTO BILINGE A.N.L.: MATHS 2

MATHS

Types of population pyramid

While all countries' population pyramids differ, four types have been identified by the fertility and

mortality rates of a country.

Stable pyramid - A population pyramid showing an unchanging pattern of fertility and mortality.

Stationary pyramid - A population pyramid typical of countries with low fertility and lowmortality, also called a constrictive pyramid.

Expansive pyramid - A population pyramid showing a broad base, indicating a high proportionof children, a rapid rate of population growth, and a low proportion of older people. This wide

base indicates a large number of children. A steady upwards narrowing shows that more peopledie at each higher age band. This type of pyramid indicates a population in which there is a high

birth rate, a high death rate and a short life expectancy. This is the typical pattern for lesseconomically developed countries, due to little access to and incentive to use birth control,negative environmental factors (for example, lack of clean water) and poor access to health care.

Constrictive pyramid - A population pyramid showing lower numbers or percentages of younger people. The country will have more people who are generally older.

Uses of population pyramids

Population pyramids can be used to find the number of economic dependents being supported ina particular population, In short: to observe the natural increase, birth, and death rate.

Activities:

Answer the following questions:1. What is a population pyramid?2. Give another name for population pyramid.3. Why is it named population pyramid?4. Place the following names on the graph: X-axis ,Y-axis, base, bar graphs.5. How many types of population pyramids are there? What are their differences?6. What are population pyramids used for?