CREATE TABLE table_name_41 (episode_number INT, air_date VARCHAR)

What kind of Episode Number has a Air Date on 29 june 2007?
SELECT AVG(episode_number) FROM table_name_41 WHERE air_date = "29 june 2007"
SELECT AVG("episode_number") FROM "table_name_41" WHERE "29 june 2007" = "air_date"