/kloc-in the 7th century, the Italian mathematician BiagioPelacani first proposed the prototype of the square difference formula and applied it to the error analysis of a set of data. 65438+In 1950s, Swedish mathematician AndersLexell expanded and perfected the research of Pelacani, and proposed a calculation method similar to the modern variance formula.
At the end of 19, the British mathematician R.A.Fisher further developed the square difference formula and put forward the least square method, which solved the relationship between multiple variables and was considered as one of the founders of modern statistics.
At the beginning of the 20th century, Chi-square (χ? The discovery of test brings a new idea, which extends variance to the study of classified data. In 1950s, with the rise of Bayesian statistics, classical statistical methods such as square difference formula were challenged, and people began to re-examine the limitations and application scope of these classical formulas. ?
2 1 century, with the advent of the era of big data, the square difference formula is still an indispensable tool in all kinds of statistical analysis, but its application field has undergone tremendous changes and needs to be studied and expanded in a broader context.
In a word, variance formula, as a classical statistical tool, has been continuously developed and improved in recent hundreds of years. With the progress of mathematics and statistics, people have new thoughts and explorations on its application, thus expanding its application scope.
Although various new methods and techniques have appeared in the field of modern statistics, variance formula is still an important and basic statistical method, which is widely used in various data analysis and experimental research.