user: Question: Name the viewers for production code for 3X6704
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'U.S. viewers (million)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [24.0, 1.0, '"Wednesday"', 'Christopher Chulack', 'Jonathan Lisco', 'January17,2012', '3X6701', '1.76']
SQL:

assistant: SELECT "U.S. viewers (million)" FROM "Table" WHERE "Production code" = '3X6704';