text: -- For each account, determine the average amount of each type of paper they purchased across their orders. Your result should have four columns - one for the account name and one for the average quantity purchased for each of the paper types for each account.
  SELECT a.name, AVG(o.standard_qty) avg_stand, AVG(o.gloss_qty) avg_gloss, AVG(o.poster_qty) avg_post
  FROM accounts a
  JOIN orders o
  ON a.id = o.account_id
  GROUP BY a.name;
  
  
  -- For each account, determine the average amount spent per order on each paper type. Your result should have four columns - one for the account name and one for the average amount spent on each paper type.
  SELECT a.name, AVG(o.standard_amt_usd) avg_stand, AVG(o.gloss_amt_usd) avg_gloss, AVG(o.poster_amt_usd) avg_post
  FROM accounts a
  JOIN orders o
  ON a.id = o.account_id
  GROUP BY a.name;
  
  
  -- Determine the number of times a particular channel was used in the web_events table for each sales rep. Your final table should have three columns - the name of the sales rep, the channel, and the number of occurrences. Order your table with the highest number of occurrences first.
  SELECT s.name, w.channel, COUNT(*) num_events
  FROM accounts a
  JOIN web_events w
  ON a.id = w.account_id
  JOIN sales_reps s
  ON s.id = a.sales_rep_id
  GROUP BY s.name, w.channel
  ORDER BY num_events DESC;
  
  
  -- Determine the number of times a particular channel was used in the web_events table for each region. Your final table should have three columns - the region name, the channel, and the number of occurrences. Order your table with the highest number of occurrences first.
  SELECT r.name, w.channel, COUNT(*) num_events
  FROM accounts a
  JOIN web_events w
  ON a.id = w.account_id
  JOIN sales_reps s
  ON s.id = a.sales_rep_id
  JOIN region r
  ON r.id = s.region_id
  GROUP BY r.name, w.channel
  ORDER BY num_events DESC;