CREATE TABLE table_75603 ("Call sign" TEXT, "Frequency MHz" FLOAT, "City of license" TEXT, "ERP W" FLOAT, "Class" TEXT, "FCC info" TEXT)

Call sign of k231bg has what sum of erp w?
SELECT SUM("ERP W") FROM table_75603 WHERE "Call sign" = 'k231bg'
SELECT SUM("ERP W") FROM "table_75603" WHERE "Call sign" = 'k231bg'