user: Question: What is the Air Date that has a 18–49 larger than 1.9, less than 7.54 viewers and a rating less than 4.9?
Columns: ['Episode #', 'Title', 'Air Date', 'Rating', 'Share', '18–49', 'Viewers', 'Rank']
Types: ['real', 'text', 'text', 'real', 'real', 'real', 'real', 'text']
Sample row: [42.0, '"The Manhattan Project"', 'September 25, 2008', 6.6, 11.0, 3.3, 9.77, '#26']
SQL:

assistant: SELECT "Air Date" FROM "Table" WHERE "18–49" > 1.9 AND "Viewers" < 7.54 AND "Rating" < 4.9;