CREATE TABLE table_79684 ("Call sign" TEXT, "Frequency MHz" FLOAT, "City of license" TEXT, "ERP W" FLOAT, "Class" TEXT, "FCC info" TEXT)

What is the total erp w of class c3, which has a frequency mhz less than 89.9?
SELECT COUNT("ERP W") FROM table_79684 WHERE "Class" = 'c3' AND "Frequency MHz" < '89.9'
SELECT COUNT("ERP W") FROM "table_79684" WHERE "Class" = 'c3' AND "Frequency MHz" < '89.9'