What is the average sales of the journals that have an editor whose work type is 'Photo'?
SELECT avg(T1.sales) FROM journal AS T1 JOIN journal_committee AS T2 ON T1.journal_ID  =  T2.journal_ID WHERE T2.work_type  =  'Photo'
SELECT avg(T1.sales) FROM journal AS T1 JOIN journal_committee AS T2 ON T1.journal_ID  =  T2.journal_ID WHERE T2.work_type  =  'Photo'
[{'avg(T1.sales)': 4660.25}]