CREATE TABLE table_70353 ("Call sign" TEXT, "Frequency MHz" FLOAT, "City of license" TEXT, "ERP W" FLOAT, "Class" TEXT, "FCC info" TEXT)

Name the sum of ERP W for class of d and frequency mhz of 98.7
SELECT SUM("ERP W") FROM table_70353 WHERE "Class" = 'd' AND "Frequency MHz" = '98.7'
SELECT SUM("ERP W") FROM "table_70353" WHERE "Class" = 'd' AND "Frequency MHz" = '98.7'