Introduction to Central Tendency

Data normally has a tendency to group around its middle numbers. So if you were to gather a random group of men, you will notice that while a few are quite tall and another few are short, most will be about the average height of the group. Some number in the middle of the heights of the group will therefore be able to represent the group as a whole. Three such measures of central tendency, which can be used to represent the group are mean, mode and median.

Normal Distribution

Most things in nature tend to follow the normal distribution. It has only one peak and is shaped like a bell so is often also refferred to as the"bell curve". Physicists sometimes refer to this distribution as the "Gaussian Distribution". 

Normal Distribution