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'
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 = value
What is the average sales of the journals that have an editor whose work type is 'Photo ' ?