Table: tv_episodes_15
Columns: no
col
title
directed_by
written_by
u_s_air_date
production_code
u_s_viewers_million

Question: When 3t7458 is the production code who are the writers?
SQL: SELECT "written_by" FROM tv_episodes_15 WHERE "production_code" = '3T7458'

Question: When there are  3.39 million u.s viewers what is the production code?
SQL: SELECT "production_code" FROM tv_episodes_15 WHERE "u_s_viewers_million" = '3.39'

Question: When 3t7461 is the production code who is the director?
SQL: SELECT "directed_by" FROM tv_episodes_15 WHERE "production_code" = '3T7461'