The problem of estimating the variance of the ratio estimator in sampling with probability proportional to aggregate size is investigated. The form of nonnegative unbiased variance estimators is found ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

Google made a significant event out of Leap Day 2012 by releasing a new version of Google Analytics featuring Data Sampling. The idea behind data sampling is commonplace in any statistical analysis: ...

Ali Hussain has a background that consists of a career in finance with large financial institutions and in journalism covering business. Vikki Velasquez is a researcher and writer who has managed, ...