CREATE TABLE table_5487 ("Frequency" FLOAT, "Callsign" CLOB, "Brand" CLOB, "Format" CLOB, "City of License" CLOB, "Website" CLOB, "Webcast" CLOB)

What's the highest frequency of the KBDR callsign?
SELECT MAX("Frequency") FROM table_5487 WHERE "Callsign" = 'kbdr'
SELECT MAX("Frequency") FROM "table_5487" WHERE "Callsign" = 'kbdr'