Data about gender and age groups in a population can seem overwhelming if laid out as raw numbers. To better organise this data, population pyramids are used. Named for their tendency to form triangles, or pyramids, population pyramids visually represent the citizens of an area as determined by their age and gender. These graphs are split into two halves, with the left side of the graph representing males and the right side representing females. Think of a population pyramid as two horizontal bar graphs placed back to back.
- Skill level:
Things you need
- Population data
- Coloured pencils
List between five and 10 age ranges for the males in your data. For example, the ranges can be 0 to 10 years old, 11 to 25, 26 to 40, 41 to 60 and finally, over 61.
Write down the number of males in each age range. For example, there might be 1,000 males between the ages of 0 and 10 years old.
Repeat for the females. Use the same age ranges.
Draw a horizontal line near the bottom of a sheet of paper. Draw a vertical line extending up from the centre of the horizontal line.
Split the horizontal line into equal sections with short vertical lines. Each section represents a population increment. For example, each section represents 1,000 people.
Write down the population increments starting with zero on the centre of the horizontal line. Work from the centre to the left first, with each section increasing by your chosen increment. Work to the right with the same increments. For example, the section to the left and right of the centre will both represent 1,000 people, and the next line out on both sides represents 2,000 people.
Split the vertical line into as many sections as you have age ranges. For example, if you have seven age ranges, there will be seven increments on the vertical line.
Plot the population of males among the first age range. If you have 1,000 males from 0 to 10 years old, the first point would one increment to the left of the centre and one increment up from the bottom.
Plot the population of females in the first age range. They will extend up from the bottom line and to the right of the centre line.
Colour in the area of the first plotted male point. The colour extend up one increment on the vertical line and reach the end of the increment on the horizontal line that represents the population size. Repeat with the female point, using a different colour.
Continue plotting and colouring in sections of the graphs until you reach the top. Label each side of the pyramid with the specified gender.
- 20 of the funniest online reviews ever
- 14 Biggest lies people tell in online dating sites
- Hilarious things Google thinks you're trying to search for