Looking for meaningful variables
Sometimes a simple transformation of the raw data that have been collected provides a variable whose values are more meaningful or highlight a different aspect of the data.
European population
African calorie intake
Other examples
The Gross Domestic Product (GDP) of countries is often reported. It is usually more meaningful to divide by the population size to obtain the GDP per capita.
When the values of imports or exports are reported over a series of years, it is usual to take account of inflation by dividing by a price index (e.g. the consumer price index).
Always think carefully about the variables you have been given. Are they accurate? Are there other variables that would be more informative?