Population Pyramids

Today in class we learned about population pyramids. We use population pyramids to analyze growth or decline of fertility, mortality, and migration in cites. There are three basic shapes to populations pyramids. There is the Christmas tree the shows that growth rates are slow, there are high birth rates and short life expediencies. There is also the box which shows low infant mortality, slow population growth, and long life expectancy. Lastly there's the cup that consists of low birth rates, shrinking population, and long life expediencies.