user: Question: Which conference joined in 1954 with a Beavers mascot?
Columns: ['School (IHSAA ID#)', 'Location', 'Mascot', '# / County', 'Year Joined', 'Year Left', 'Conference Joined']
Types: ['text', 'text', 'text', 'text', 'real', 'real', 'text']
Sample row: ['Delphi', 'Delphi', 'Oracles', '08 Carroll', 1954.0, 1956.0, 'Hoosier']
SQL:

assistant: SELECT "Conference Joined" FROM "Table" WHERE "Year Joined" = 1954.0 AND "Mascot" = 'Beavers';