Table: episodes_table_6
Columns: no_in_series
no_in_season
title
directed_by
written_by
original_air_date
u_s_viewers_millions

Question: How many millions of U.S. viewers whatched episodes written by Krystal Houghton?
SQL: SELECT "u_s_viewers_millions" FROM episodes_table_6 WHERE "written_by" = 'Krystal Houghton'

Question: How many titles were directed in series 79?
SQL: SELECT COUNT("directed_by") FROM episodes_table_6 WHERE "no_in_series" = 79

Question: Who wrote an episode watched by 19.01 million US viewers?
SQL: SELECT "written_by" FROM episodes_table_6 WHERE "u_s_viewers_millions" = '19.01'