user: Question: what is the school when signed is No and round is 50?
Columns: ['Round', 'Name', 'Position', 'School', 'Signed']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Lawrence Hutton', 'RHP', 'Greenfield High School', 'Yes']
SQL:

assistant: SELECT "School" FROM "Table" WHERE "Signed" = 'No' AND "Round" = 50.0;