CREATE TABLE table_71236 ("School" TEXT, "Location" TEXT, "Mascot" TEXT, "County" TEXT, "Enrollment IHSAA Class" TEXT, "Joined" FLOAT, "Previous Conference" TEXT)

Which previous conference is associated with Penn school?
SELECT "Previous Conference" FROM table_71236 WHERE "School" = 'penn'
SELECT "Previous Conference" FROM "table_71236" WHERE "School" = 'penn'