1. Population Pyramids
(5:01) ‘Population pyramids: Powerful predictors of the future - Kim Preshoff’

2. Class mini-census (survey of the population)
How many people live in your household?
Add up the total & divide by the number surveyed
Average Canadian household has 2.5 people
Average Mexican household has 3.8 people
Average American household has 2.6 people

3. Class mini-census
2. What is the average age of each person in your household?
Find the median age by writing out all of the ages from highest to lowest & locating the middle number
Median age of Canadians is 39.8 years old
Median age of Mexicans is 27.3 years old
Median age of the United States is 36.8 years old

4. Class mini-census
3. How many people in your household were born outside of Mexico?
Add up the answers, divide by the number surveyed & multiply by 100 to get the percentage
Percentage of Canadians born outside of Canada is 20.6%
Percentage of Americans born outside the USA is 13.7%
Mexico no se?

5. Interpreting POPULATION PYRAMIDS
What you should understand: the characteristics of the 4 types of population pyramids

6. Population Pyramids
Population pyramids show the age/sex structure of a country
Tells you what % of the population is a certain age and gender
Groups put into 5 year categories (cohort)

7. RAPIDLY EXPANDING Very high birth rate
Population growing very fast (3-4% per year)
Low income countries

8. EXPANDING High birth rate Population growing (1-2% per year)
Middle to low income countries

9. STATIONARY Births replace deaths Population not changing much at all
High income countries

10. DECLINING More deaths than births Population shrinking
Potential social problems

11. Task
Time for you to construct some population pyramids