Dropping balls demonstrate Normal Distribution

 
Notice as the balls start their drop from the top, they do so from the center. Then, as they continue to drop they end up roughly forming a pattern denoted by the black curved line. This special curve is called "Normal Distribution" and is very important to Mathematicians using Statistics.
As an example, suppose the average score on a test is 70. In the demonstration below, the peak of the curve (black line) would represent the number of people scoring 70. Using Normal Distribution a person could predict the spread of test scores. Usually there will be as many scores above 70 as there will be below. Furthermore, most of the scores would be centered close to the average score of 70, both above and below. Very few scores would be near 100 on the high end, or below 30 on the low end.
Measurements on humans performed by Lambert Quetelet (1796-1874) gave rise to the assumption that as far as their frequencies are concerned, all biological measurements follow this curve called Normal Distribution and the methods of Statistics were built upon this assumption.
Although what you see here is merely a computer simulation, rest assured that if a real model were built using pegs and steel balls, the results would be the same. Many science museums have such models.
 

Author: David Krider