Table: radio_stations_34
Columns: call_sign
frequency_mhz
city_of_license
erp_w
class
fcc_info

Question: When the call sign is wpib, what is lowest ERP W?
SQL: SELECT MIN("erp_w") FROM radio_stations_34 WHERE "call_sign" = 'wpib'

Question: Which class's call sign is wokg?
SQL: SELECT "class" FROM radio_stations_34 WHERE "call_sign" = 'wokg'

Question: The frequency 89.3 belongs to what class?
SQL: SELECT "class" FROM radio_stations_34 WHERE "frequency_mhz" = 89.3