CREATE TABLE table_28960 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Director" TEXT, "Writer ( s ) " TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( million ) " TEXT)

Name the production code for 60 number in series
SELECT "Production code" FROM table_28960 WHERE "No. in series" = '60'
SELECT "Production code" FROM "table_28960" WHERE "No. in series" = '60'