The Air Quality lab omits a crucial detail from its third question — "Which city IN THE UNITED STATES had the highest ozone readings?" The OpenAQ data set is worldwide, and measured in two different units. It’s a little frustrating to work through and get the wrong answer because the constraint "in the US" isn’t mentioned.
If you watch the lecture again, at about 0:40 into the lab the problem statement includes this paragraph:
You have been asked to identify the top regions in the US with the highest average Ozone levels ...
More important though – did you learn anything about using Athena to query datasets in S3, or did you already know how to do this?
Hunting for environmental data online is just like looking for a needle in a haystack. The lab needs to be more less "data hunting" and more "data usage" /solutions oriented. I am still looking for data after a week I refuse to take a Intermediate level just because of data hunting is the main problem in this lab then actually the data setup.