What is the frequency MHz in tremonton, utah with a ERP W larger than 30?
CREATE TABLE "translators" (
  "call_sign" text,
  "frequency_m_hz" real,
  "city_of_license" text,
  "erp_w" real,
  "fcc_info" text
);
SELECT "frequency_m_hz" FROM "translators" WHERE "erp_w">30 AND "city_of_license"='tremonton, utah';