Which ERP W has a Frequency MHz of 89.3 fm?
CREATE TABLE "repeaters" (
  "call_sign" text,
  "frequency_m_hz" text,
  "city_of_license" text,
  "erp_w" real,
  "fcc_info" text
);
SELECT MAX("erp_w") FROM "repeaters" WHERE "frequency_m_hz"='89.3 fm';