Thanks, Greg! Nice work on this! Your voice is quite clear and all your tech settings are in place. You are ready to record!
I will mention a couple of things that could become potential problems, but as it is, neither of them would prevent us from using your recording, if this was the real thing.
First, your volume is just a smidge on the low end. I wouldn't mess with it for now, if I were you, for fear of making it too loud, but I point it out so that you don't let it get any softer, either. Currently, you're at 87.2 dB. We aim for 89, with an acceptable range of 86-92. Again, this is well within range, just don't get any quieter.
Second, Checker is flagging this file for a moderate amount of background noise. I can't hear it, but it's quite possible that with better speakers or headphones (or better ears!) that it could be noticeable. It's up to you, and totally not mandatory, but if you want, you could try to clean up the background noise a bit. If you're using Audacity, it's very easy to do. A good how-to is found here:
https://wiki.librivox.org/index.php?title=Noisecleaning_With_Pics I myself have to do two rounds of noise cleaning for my current recording environment.
As I said, though, those two things are only potentially something to watch out for. You are all clear to start recording your chapter for this book anytime you like!
