SELECT trail_name 'Trail Name',park_name 'National Park',sub 'Sublocation',len 'Trail Length',ele 'Elevation Gain',tdiff 'Trail Difficulty',ROUND(tdiff+((udiff-tdiff)*((n-1)/(n+50))),1) AS 'Weighted Difficulty' FROM ( SELECT t.`Trail Difficulty` AS tdiff,COALESCE(AVG(u.Difficulty),0) AS udiff,COUNT(*) as n ,t.ID trail_id,t.`Trail Name` trail_name,t.`Elevation Gain` ele,t.Length len,t.Sublocation sub ,p.Name park_name,p.State state FROM UserReview u RIGHT JOIN Trails t ON u.Trail_ID=t.ID INNER JOIN Parks p ON t.`National Park`=p.Name GROUP BY t.`Trail Name` ) AS user_diff