I matched my output values as "Counts" due to Question 1 and 3 showing data for counts, but the solution output's headers called out minutes.
I created two outputs for question 4, one with all flight cancelations for the originally included dataset and another that only included the joined data, both do not match the Question 4 output of 44,777.
I have to admit, I found this Challenge quite confusing, espacially because the solution didn't really match the questions.
Tried to replicate as much as possible the solution, but I have to mention that the solution output has the number of flights delayed by airline (Q1) and by Airport (Q3) not the total number of minutes. I also wondered if the cancelled flights should have been removed from the lot of delayed flights to answer these two questions. For Q4, as mentioned by others, the solution doesn't narrow down the cancelled flights to the summer period, has way more flights in there.
All in all a nice little challenge, I always enjoy analysing flight related data 🙂
Just a suggestion: Please validate the grammar, phrasing of the question(s), outputs, etc. before posting a weekly challenge.
I believe the wording and outputs are confusing many people and not generating a learning experience.