CREATE TABLE table_79689 ("Call sign" TEXT, "Frequency MHz" FLOAT, "City of license" TEXT, "ERP W" FLOAT, "Class" TEXT, "FCC info" TEXT)

What is the highest erp w with a 90.5 frequency mhz?
SELECT MAX("ERP W") FROM table_79689 WHERE "Frequency MHz" = '90.5'
SELECT MAX("ERP W") FROM "table_79689" WHERE "Frequency MHz" = '90.5'