A family of exponential-type estimator for estimating population mean in two-phase sampling when the proportion auxiliary character is available proposed this paper. Theoretically, bias and minimum square error (MSE) are obtained. The expression MSE compared with existing estimators literature. optimum values parameters determined. An empirical study was carried out by comparing some reviewed l...

This paper considers some efficient combined and separate classes of estimators the population mean in presence bivariate auxiliary information under stratified ranked set sampling. The square error MSE expressions proffered are derived to first order approxima...