user: Question: What is the lowest child sex ratio in groups where employment is 31.3%?
Columns: ['Religious group', 'Population %', 'Growth (1991–2001)', 'Sex ratio (total)', 'Literacy (%)', 'Work participation (%)', 'Sex ratio (rural)', 'Sex ratio (urban)', 'Sex ratio (child)']
Types: ['text', 'text', 'text', 'real', 'text', 'text', 'real', 'real', 'real']
Sample row: ['Hindu', '80.46%', '20.3%', 931.0, '65.1%', '40.4%', 944.0, 894.0, 925.0]
SQL:

assistant: SELECT MIN("Sex ratio (child)") FROM "Table" WHERE "Work participation (%)" = '31.3%';