CREATE TABLE table_203_721 (id DECIMAL, "school" TEXT, "location" TEXT, "control" TEXT, "type" TEXT, "enrollment" DECIMAL, "founded" DECIMAL)

which us technological university has the top enrollment numbers ?
SELECT "school" FROM table_203_721 ORDER BY "enrollment" DESC LIMIT 1
SELECT "school" FROM "table_203_721" ORDER BY "enrollment" DESC NULLS LAST LIMIT 1