Table: x_factor_uk_series
Columns: episode
air_date
official_itv1_rating
weekly_rank
share

Question: What is the Official ITV1 rating for auditions 4?
SQL: SELECT "official_itv1_rating" FROM x_factor_uk_series WHERE "episode" = 'auditions 4'

Question: What is the lowest official ITV1 rating with 45.4% share?
SQL: SELECT MIN("official_itv1_rating") FROM x_factor_uk_series WHERE "share" = '45.4%'