2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/171346This study proposes improved chain-ratio type estimator for estimating population mean using some known values of population parameter(s) of the second auxiliary character. The proposed estimators have been compared with two-phase ratio estimator and some other chain type estimators. The performances of the proposed estimators have been supposed with a numerical illustration.11 pagesGeneral Mathematics65C60text