He's in the 5th grade right? The average 5th grader is around 4,7ft and since his nose is 2/3 his body size and 4.7/3=1.566 and 1.566x2=3.132, his nose is probably about 3.132ft long. Like my ****.
Not necessarily, your physical characteristics depend on both parents and all grandparents. You may look more like one of them or as none of them at all depending on your genetic mosaic
If you're a woman, you can use makeup to help make your nose look smaller. But if you're really bothered by the size of your nose, you may want to consider plastic surgery. Nose jobs or rhinoplasty...
There are many procedures and techniques to achieve smaller, narrower, shorter straighter and so on, nose.
Firstly I recomend you trying Make-up techniques. If that won't work on you, you might...