What is the average number of hours spent practicing for students who got rejected?
SELECT avg(T1.HS) FROM player AS T1 JOIN tryout AS T2 ON T1.pID  =  T2.pID WHERE T2.decision  =  'no'
SELECT avg(T1.HS) FROM player AS T1 JOIN tryout AS T2 ON T1.pID  =  T2.pID WHERE T2.decision  =  'no'
[{'avg(T1.HS)': 925.0}]