CREATE TABLE table_28422 ("No." FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "U.S. viewers  ( million ) " CLOB, "Rank  ( week ) " FLOAT, "Original air date" CLOB, "Production code" CLOB)

What is the weeks rank for the episode with the production code 1alf05?
SELECT MAX("Rank (week)") FROM table_28422 WHERE "Production code" = '1ALF05'
SELECT MAX("Rank (week)") FROM "table_28422" WHERE "Production code" = '1ALF05'