首页   按字顺浏览 期刊浏览 卷期浏览 On the Exact Variance of Products
On the Exact Variance of Products

 

作者: LeoA. Goodman,  

 

期刊: Journal of the American Statistical Association  (Taylor Available online 1960)
卷期: Volume 55, issue 292  

页码: 708-713

 

ISSN:0162-1459

 

年代: 1960

 

DOI:10.1080/01621459.1960.10483369

 

出版商: Taylor & Francis Group

 

数据来源: Taylor

 

摘要:

A simple exact formula for the variance of the product of two random variables, say,xandy, is given as a function of the means and central product-moments ofxandy. The usual approximate variance formula forxyis compared with this exact formula; e.g., we note, in the special case wherexandyare independent, that the “variance” computed by the approximate formula is less than the exact variance, and that the accuracy of the approximation depends on the sum of the reciprocals of the squared coefficients of variation ofxandy. The case wherexandyneed not be independent is also studied, and exact variance formulas are presented for several different “product estimates.” (The usefulness of exact formulas becomes apparent when the variances of these estimates are compared.) Whenxandyare independent, simple unbiased estimates of these exact variances are suggested; in the more general case, consistent estimates are presented.

 

点击下载:  PDF (524KB)



返 回