Principle of the mean is average of quantity of some similar kind of thing.
Example: one is going to average the annual rainfall (cm.) Then he needs to take rainfall data of 12 months, add it and divide the summation by 12. It will give mean value.
Example: When a farmer is going to measure the whole years production its not possible by using the formula of mean. Because it involves various kind of data.
Explanation:
In statistics, three basic component is mean, median and mode.
For e.g. Mean implies its importance mainly in climatological data, score based data.
Median easily provide the required value in height and weight of students.
Mode provides right value when same price/kilo is repeating in case of two different product.