user: Question: What is the average decile of the school with a State authority and a roll number of 888?
Columns: ['Name', 'Years', 'Gender', 'Area', 'Authority', 'Decile', 'Roll']
Types: ['text', 'text', 'text', 'text', 'text', 'real', 'real']
Sample row: ['Auckland Normal Intermediate', '7–8', 'Coed', 'Mount Eden', 'State', 9.0, 731.0]
SQL:

assistant: SELECT AVG("Decile") FROM "Table" WHERE "Authority" = 'State' AND "Roll" = 888.0;