Graphs and population
(Explanations were taken from Richmond's textbook Geography and History, 2004.ISBN:84-294-9216-X )
Maths web task
What are graphs? Have a look at this visual explanation of them. Different types of graphs are used to represent demographic data. Let's have a look at them:
THE LINE OR LINEAR GRAPH
Through one or more lines it represents the values of a variable. It is the most commonly used to represent the evolution of a variable over a period of time.
Located on the horizontal axis, is the time variable ( for example the years), and on the vertical axis, the variable that represents, for example, the number or inhabitants. The values are marked at the corresponding height on the vertical axis and then they are joined together with a line.
SIMPLE BAR CHARTS
It represents the values of a variable in a given spatial unit (continents, countries, etc) through columns or bars, which have proportional length to the quantity they represent.
This one represents the countries with more population density.
Countries, years are located on the horizontal axis and the corresponding values are marked with bars according to the vertical axis.
THE PIE GRAPHS
It represents, through sectors proportional to the value they represent, the distribution of a phenomenon: for example the distribution of the world's population.
It is easy to draw: If 100 (%) is 360º, 10% is at X. X are the degrees of the circumference obtained.
If you would like to have more practice on this topic,click here
EXERCISES: WHAT GRAPH/S WOULD YOU USE IN THESE SITUATIONS?
Infant mortality rate:
This entry gives the number of deaths of infants under one year old in a given year
per 1,000 live births in the same year.
Lola Aceituno and Mª Jesús López