CREATE TABLE table_27045 ("Episode" FLOAT, "First Air Date" TEXT, "Rating  ( 18\\u201349 ) " TEXT, "Share  ( 18\\u201349 ) " FLOAT, "Viewers  ( millions ) " TEXT, "Rank  ( timeslot ) " TEXT, "Rank  ( night ) " TEXT)

what episode number had 11.73 million viewers?
SELECT "Episode" FROM table_27045 WHERE "Viewers (millions)" = '11.73'
SELECT "Episode" FROM "table_27045" WHERE "Viewers (millions)" = '11.73'