SELECT c.LastName
, AVG(s.Length) AS [CiagrLength]
, CEILING(AVG(s.RingRange)) AS [CiagrRingRange]
FROM Clients AS c
JOIN ClientsCigars AS cc ON c.Id = cc.ClientId
JOIN Cigars AS cig ON cc.CigarId = cig.Id
JOIN Sizes AS s ON cig.SizeId = s.Id
GROUP BY c.LastName
ORDER BY CiagrLength DESC