CREATE TABLE table_43709 ("Call sign" TEXT, "Frequency MHz" FLOAT, "City of license" TEXT, "ERP W" FLOAT, "FCC info" TEXT)

What is average frequency MHZ when is in portales, new mexico?
SELECT AVG("Frequency MHz") FROM table_43709 WHERE "City of license" = 'portales, new mexico'
SELECT AVG("Frequency MHz") FROM "table_43709" WHERE "City of license" = 'portales, new mexico'