Stratified mean-per-unit sampling is a key tool used by auditors. The popularity of this statistical procedure arises from its unique ability to produce trustworthy ...

Greg DePersio has 13+ years of professional experience in sales and SEO and 3+ years as a writer and editor. Robert Kelly is managing director of XTS Energy LLC, and has more than three decades of ...

Sean Ross is a strategic adviser at 1031x.com, Investopedia contributor, and the founder and manager of Free Lances Ltd. Gordon Scott has been an active investor and technical analyst or 20+ years. He ...

Historically, public opinion surveys have relied on the ability to adjust their datasets using a core set of demographics – sex, age, race and ethnicity, educational attainment, and geographic region ...

Oct. 8, 2008— -- Surveys based on a random sample of respondents are subject to sampling error – a calculation of how closely the results reflect the attitudes ...