“population covariance”的概念、定义、翻译、参考文献-科学参考

population covariance

Statistics

For two random variables X and Y, this is the difference between the expected value of their product and the product of their separate expected values. It is denoted by Cov (X,Y): $population covariance$
If X and Y are independent then Cov(X, Y)=0. However, if Cov(X, Y)=0 then X and Y may not be independent. A useful result is
Var(aX+bY)=a²Var(X)+2ab Cov(X, Y)+b²Var(Y), where Var denotes variance, and a and b are constants. The term 'covariance' was used by Sir Ronald Fisher in 1930. See also population correlation coefficient.

单词	population covariance
释义	population covariance Statistics For two random variables X and Y, this is the difference between the expected value of their product and the product of their separate expected values. It is denoted by Cov (X,Y): $population covariance$ If X and Y are independent then Cov(X, Y)=0. However, if Cov(X, Y)=0 then X and Y may not be independent. A useful result is Var(aX+bY)=a²Var(X)+2ab Cov(X, Y)+b²Var(Y), where Var denotes variance, and a and b are constants. The term 'covariance' was used by Sir Ronald Fisher in 1930. See also population correlation coefficient.
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