Table: radio_stations_tamaulipas
Columns: frequency
callsign
brand
city_of_license
type

Question: What is City of License, when Frequency is greater than 1380?
SQL: SELECT "city_of_license" FROM radio_stations_tamaulipas WHERE "frequency" > 1380

Question: What is Brand, when Frequency is "640"?
SQL: SELECT "brand" FROM radio_stations_tamaulipas WHERE "frequency" = 640

Question: What is the average Frequency, when Type is "Norteño", and when Brand is "La Cotorra"?
SQL: SELECT AVG("frequency") FROM radio_stations_tamaulipas WHERE "type" = 'norteño' AND "brand" = 'la cotorra'

Question: What is Type, when Frequency is "1480"?
SQL: SELECT "type" FROM radio_stations_tamaulipas WHERE "frequency" = 1480

Question: What is the sum of Frequency, when Type is "Christian Pop"?
SQL: SELECT SUM("frequency") FROM radio_stations_tamaulipas WHERE "type" = 'christian pop'

Question: What is the Type, when Callsign is "Xetam"?
SQL: SELECT "type" FROM radio_stations_tamaulipas WHERE "callsign" = 'xetam'