Chart for avg posting times compaired to reach

I've been trying to figure out a way to compare some Facebook data. I'm trying to figure out if there is a correlation between posting times and the reach of the posts. I don't want a long day-by-day comparison, but rather a chart that shows the average reach for posts between 8am-10am, 10am-12pm, or some similar time grouping. I've tried a variety of different chart options that I know how to do, but none of them are getting me the result I want, so I thought I'd turn to the experts!
Attached is a sample of the the data I have.
Thanks in advance!

With an extra column and a pivot table. You have to adjust the formula to the periods you want to see.