SELECT n.note, f.kbz FROM noten n
INNER JOIN personen p ON p.personen_id = n.personen_id AND (p.vorname = 'Georg' 
AND p.name = 'Rauch')
INNER JOIN studenten s ON s.personen_id = p.personen_id
INNER JOIN unterricht u ON u.unterricht_id = n.unterricht_id
INNER JOIN faecher f ON f.fach_id = u.fach_id
WHERE n.note < (SELECT AVG(n.note) FROM noten n
INNER JOIN personen p ON p.personen_id = n.personen_id AND (p.vorname = 'Georg' 
AND p.name = 'Rauch')
INNER JOIN studenten s ON s.personen_id = p.personen_id)