Marshall Hargrave is a stock analyst and writer with 10+ years of experience covering stocks and markets, as well as analyzing and valuing companies. Dr. JeFreda R. Brown is a financial consultant, ...

variance formulas for stratified samples may often be regarded as inappropriate. In simple sampling the post-stratified estimator of the total and mean are known and can be found, for example, in ...

Although genome-wide association studies (GWASs) have identified numerous loci associated with complex traits, imprecise modeling of the genetic relatedness within study samples may cause substantial ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. David Kindness is a Certified Public ...