Guided Project: Analyzing CIA Factbook Data Using SQL -> DOUBT

Hello! On the last step of the guided project I find one difference between the results of two different queries. This is how I made it:

This is the solution given:

I can’t understand why my query did not return some countries that were returned by the second one.

Example: why my query didn’t return Iraq or South Korea, if they meet the criteria I defined for filtering? I didn’t see why the absence of WHERE name <> 'World' is altering the results.


The World row in this table has a population of over 7 billion. If you don’t exclude this row, then the average population will be greater and then fewer countries will fulfill this requirement. The opposite goes to the area. If you don’t exclude World then the average will be greater and therefore more countries will fulfill this requirement.

Try to select the average population and area with and without the World row and you’ll notice the difference.

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