CREATE TABLE table_4178 ("Position" FLOAT, "Top MC" TEXT, "Year inducted" FLOAT, "Appearances" FLOAT, "Peak ranking" FLOAT)

List all the MCs with peak ranking of 6 who were inducted in 2007.
SELECT "Top MC" FROM table_4178 WHERE "Year inducted" = '2007' AND "Peak ranking" = '6'
SELECT "Top MC" FROM "table_4178" WHERE "Peak ranking" = '6' AND "Year inducted" = '2007'