title: Inner join and average in SQL
body: <p>I'm new to SQL thus the question. I'm trying to query the following. Given the CITY and COUNTRY tables, query the names of all the continents (COUNTRY.Continent) and their respective average city populations (CITY.Population) rounded down to the nearest integer.
  The table schemas are <code>City: id, name, countryside, population</code></p>
  
  <pre><code>Country: code, name,continent, population
  </code></pre>
  
  <p>I've written the inner join, but can't seem to figure out the way to get the <code>avg</code> city population. This is my code.</p>
  
  <pre><code>SELECT COUNTRY.CONTINENT
  FROM COUNTRY 
  INNER JOIN ON 
  COUNTRY.CODE = CITY.COUNTRYCODE;
  </code></pre>
  
  <p>Any help appreciated.</p>