user: Question: How many million U.S. viewers saw the episode with production code 3X5710?
Columns: ['No. in series', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'U.S. viewers (million)']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '" Pilot "', 'Julie Anne Robinson', 'DeAnn Heline & Eileen Heisler', 'September30,2009', '276047', '8.71']
SQL:

assistant: SELECT "U.S. viewers (million)" FROM "Table" WHERE "Production code" = '3X5710';