CREATE TABLE table_name_31 (rank NUMBER, date VARCHAR2, mark VARCHAR2)

What is the average rank of the record on 2007-06-21 with a mark less than 91.29?
SELECT AVG(rank) FROM table_name_31 WHERE date = "2007-06-21" AND mark < 91.29
SELECT AVG("rank") FROM "table_name_31" WHERE "2007-06-21" = "date" AND "mark" < 91.29