Table: tv_episodes_4
Columns: series
season
title
directed_by
written_by
original_air_date
u_s_viewers_millions

Question: Name the number air date for 14.20 us viewers
SQL: SELECT COUNT("original_air_date") FROM tv_episodes_4 WHERE "u_s_viewers_millions" = '14.20'

Question: Name the directed by for 15.15 viewers
SQL: SELECT "directed_by" FROM tv_episodes_4 WHERE "u_s_viewers_millions" = '15.15'