Table: tv_episodes_4
Columns: no_in_series
title
directed_by
written_by
featured_character_s
original_air_date
u_s_viewers_million

Question: What are the title that have 19.48 million u.s. viewers?
SQL: SELECT "title" FROM tv_episodes_4 WHERE "u_s_viewers_million" = '19.48'

Question: Which titles have 18.73 u.s. viewers.
SQL: SELECT "title" FROM tv_episodes_4 WHERE "u_s_viewers_million" = '18.73'

Question: Who wrote all the shows with 18.73 u.s. viewers?
SQL: SELECT "written_by" FROM tv_episodes_4 WHERE "u_s_viewers_million" = '18.73'