ค่าเฉลี่ยและค่ามัธยฐาน

-- What groups are you computing statistics by?
SELECT ___,
       -- Select the mean of assets with the avg function
       ___ AS mean,
       -- Select the median
       ___(___) ___ ___ (___ ___ ___) AS median
  FROM fortune500
 -- Computing statistics for each what?
 GROUP BY ___
 -- Order results by a value of interest
 ORDER BY ___;