CREATE TABLE table_25751274_2 (rank__night_ INT, rating VARCHAR)

What is the lowest rank of an episode with a rating/share (18-49) of 1.3/4?
SELECT MIN(rank__night_) FROM table_25751274_2 WHERE rating / SHARE(18 - 49) = 1.3 / 4
SELECT MIN("rank__night_") FROM "table_25751274_2" WHERE "rating" / NULLIF(SHARE(-31), 0) = 1.3 / NULLIF(4, 0)