What Is The Average Cycling Speed For A Normal Person?

9 miles doesn't tell us much. 9 miles, open road, few to no stops, flat to rolling terrain, is different than 9 miles, hilly, with headwinds. And way different than 9 miles, urban roads, traffic signals/stop signs.

4 minute miles = 15 mph.

3 minute miles = 20 mph.
There's no such thing as an average for a "normal" person, at least in my opinion. As many have alluded to, there are just too many variables to come to a number. You may look at elite races with comparable equipment, and you'll get an idea of what an average speed is. But for those of us who ride, it just depends.

I just recently purchased a Specialized Sirrus (short money at $480 + extras), a lower end commuter style flat bar bike. I purchased it for fitness. Yet, when I ride I mark my speed. I'm training for a sprint tri, and this is the bike I will use. I did a 12 mile ride this morning and averaged 18.4 mph. A few days ago did 17.93 miles in an hour, and last week a 15 mile ride averaging 18.1, and a few weeks ago a 27 mile ride averaging 17.5 mph. Point is, after gauging a few of my rides on my equipment, my average time is floating around 18, and with my equipment I think that is pretty good. And I do not pause my watch at stop lights, so it's just my overall ride average.

At some point down the road I would love to ride a bike built for speed, and take one of my normal routes to check the difference. I have a very old Raleigh road bike with drop bars in storage which hasn't been out for decades. But I bet my Sirrus goes as fast due to equipment upgrades over the years.

Keep riding and building up your database of riding. Then you'll know the only important average that matters - yours.
What exactly is a "normal" person? Don't think I have heard heard of that before! haha.
So many variable, you have to try a dry run on your day off to really see.
Although 15 to 25 KM per hour is average.
Around 14 mph all together possibly. It honestly depends though. It all depends on how fit you are and how much muscle endurance you have.
I average anywhere from 8 to 17 MPH, depending on the day, time, weather, hills, etc, and just how I feel. I've ridden with riders who struggled to maintain 8 MPH and ridden with riders who averaged 19 MPH out of the gate, so it depends on the bike you ride, the gear you have to carry, your fitness, and the road conditions. Figure at least an hour to do the 9 miles to be safe and do a dry run. It will vary depending on traffic, weather, etc. Also plan on clean-up time as you may perspire and need to change clothing. Clothing may also mean saddle bags, baskets, etc, which all add weight and wind resistance, so too many variables to give you a good idea, but always plan on being slower than you think you might be.