CREATE TABLE table_22347090_4 (no_in_series NUMBER, us_viewers__million_ VARCHAR2)

Which series number had 1.98 million viewers?
SELECT MIN(no_in_series) FROM table_22347090_4 WHERE us_viewers__million_ = "1.98"
SELECT MIN("no_in_series") FROM "table_22347090_4" WHERE "1.98" = "us_viewers__million_"