While arriving at the same correct answer (I got it wrong), I approached it differently.

If the population was static the past 10 years, average age should have gone from 52 to 62; instead it went from 52 to 57 only. Additionally, they concluded it is because a bunch of 65 year olds moved in, which should've further increase the average age. So in order to strengthen that conclusion, we need a bunch of 18 year olds to counterbalance the 65 year olds, so the final average age is 57.

@ said:

@ said:

David's super power is to allow adults to go back in time partially so they can be fans of and grow up with Harry Potter

I think @ is already implementing we learned in the webinar (doing some research about David and making a reference to the NYT op-ed) ;)

Unless you have done the same search, you won't know I made a reference ;)

David's super power is to allow adults to go back in time partially so they can be fans of and grow up with Harry Potter