user: Question: what episode number had 11.73 million viewers? 
Columns: ['Episode', 'First Air Date', 'Rating (18–49)', 'Share (18–49)', 'Viewers (millions)', 'Rank (timeslot)', 'Rank (night)']
Types: ['real', 'text', 'text', 'real', 'text', 'text', 'text']
Sample row: [1.0, 'January 4, 2010', '3.3', 8.0, '9.50', 'N/A', 'N/A']
SQL:

assistant: SELECT "Episode" FROM "Table" WHERE "Viewers (millions)" = '11.73';