SELECT "Lost" FROM table_39915 WHERE "Losing Bonus" = '4'
What is the Lost with a Losing Bonus that is 4?
CREATE TABLE table_39915 (
    "Club" text,
    "Played" text,
    "Drawn" text,
    "Lost" text,
    "Points for" text,
    "Points against" text,
    "Points difference" text,
    "Tries For" text,
    "Tries Against" text,
    "Try Bonus" text,
    "Losing Bonus" text,
    "Points" text
)