### What is the Meaning & Definition of variance

Theory of probability and statistics, the variance is the measure of dispersion that is a random variable with respect to its hope. The variance is related to the standard deviation or standard deviation, which is denoted by the Greek letter sigma called and that will be the square root of the variance.
To calculate the variance will be necessary to follow the following steps: first we have to calculate the average, i.e., the average of the numbers, then, for each number, will have to subtract the average and raise the result to the square and finally the mean of these squared differences.
The main function and utility which can be found at variance is that it allows us to know and determine what is normal, what is great, what is small, that which is extra large or even what is extra small.
For example, if we take several breeds of dogs and the idea is to determine which of them is larger and which the smaller, without a doubt, the best way to know the answer to this question will be the application of the formula for the variance.

Article contributed by the team of collaborators.