Table: episode_stats_2
Columns: no_in_series
no_in_season
title
directed_by
written_by
original_air_date
production_code
u_s_viewers_million

Question: how many series had 6.55 u.s. viewers (million) and were directed by pete michels
SQL: SELECT COUNT("no_in_series") FROM episode_stats_2 WHERE "u_s_viewers_million" = '6.55' AND "directed_by" = 'Pete Michels'

Question: how many series have production code 8acx05
SQL: SELECT "no_in_series" FROM episode_stats_2 WHERE "production_code" = '8ACX05'

Question: how many u.s. viewers (million) have seen a production written by chris sheridan & danny smith
SQL: SELECT COUNT("u_s_viewers_million") FROM episode_stats_2 WHERE "written_by" = 'Chris Sheridan & Danny Smith'

Question: which production codes were written by andrew goldberg
SQL: SELECT "production_code" FROM episode_stats_2 WHERE "written_by" = 'Andrew Goldberg'

Question: Which production code had original air dated february20,2011
SQL: SELECT "production_code" FROM episode_stats_2 WHERE "original_air_date" = 'February20,2011'