TotalPopulation Measure Purpose
What is the purpose of having the Total Population measure in this example? How does measure work in a different scenario where it wouldn't just be equal to one of the columns?
TotalPopulation summarizes the total population from the column. It is a separate formula meaning that you can place TotalPopulation in a card visual and see the total figure for population, or you can add attributes and see the population by country, etc in another chart. The measure can be used with other columns or can be used on it's own.