Question: When the call sign is WPIB, what is lowest ERP W?
SQL: SELECT MIN("ERP W") FROM "2-12840409-1" WHERE "Call sign" = 'WPIB';

Question: Which class's call sign is WOKG?
SQL: SELECT "Class" FROM "2-12840409-1" WHERE "Call sign" = 'WOKG';

Question: The frequency 89.3 belongs to what class?
SQL: SELECT "Class" FROM "2-12840409-1" WHERE "Frequency MHz" = 89.3;