What is the Meaning & Definition of variance (statistics and mathematics)


Use in statistics: measure of the variability or dispersion

At the behest of the theory of probability, which is the branch within mathematics which focuses on the study of random phenomena, i.e. those whose outcome is not predictable, the variance of a random variable is a measure of the variability or dispersion, indicating precisely the variation of a distribution, distinguish through a value if a variable different scores are far removed from the average. Higher value, the greater the variability, and lower value, more homogeneous will be the measure.
The concept is especially used in the statistics which serves to identify the average quadratic deviation of a variable of a random nature, taking into consideration the average of the same value.

The English scientist Sir Ronald Aylmer Fisher, responsible for his coinage

The English scientist Sir Ronald Aylmer Fisher was responsible for the creation of the concept in the first decade of the last century.
It would be in an agricultural station where they would begin their studies and analysis of variance. I had to deal with the study of a long period of cultivated crops and then in this work is the concept.
Aylmer has been considered the father of modern statistics and a genius in the matter and many others for the contributions made to this regard.
Many distinctions and the important title of Sir was awarded.
The analysis of variance are a series of statistical models more associated procedures and where the variance will be shown in different components.
Usually at the hands of the concept of variance is another partner, the typical or standard deviation representing the extent of dispersion of those of reason and interval variables. This concept also presents an extended usage at the behest of the statistics, in the field of the descriptive and to calculate it should be starting from the variance and calculating the square root from it.
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