check activities.. especially second to last one (first should be good)

[carriewright11]

I struggled with the penultimate exercise for this chapter (7.5.1). I was working off a version of the code from previous chapters (which I think should have been up to date) but it didn't quite match the "before" code I was meant to update. So, I downloaded the suggested project files (section 7.4). However, these seemed to match the "before" expectation even less well. I think they are actually the "after" solution.

Originally posted by @obigriffith in #95 (comment)