In the month of February of a given year - there were 13,318 cancelled flights out of 531,035 total flights in Europe.

In that month, Heathrow airport had 1,558 flights out of 29,949 of its total flights cancelled. We would like to look at whether or not Heathrow airport's performance is any different than the performance of Europe's airports as a whole at a 5% level of significance.

Please do state the null hypothesis.

(Make sure that your null hypothesis is clear and unambiguous.)