IMPROVED ESTIMATORS OF POPULATION MEAN USING AUXILIARY VARIABLES IN RANKED SET SAMPLING.

This paper presents some improved estimators of population mean using auxiliary variables in Ranked Set Sampling. We have derived the expressions for bias and mean square errors up to the first order of approximation and shown that the proposed estimators under optimum conditions are more efficient than other estimators taken in this paper. In an attempt to verify the efficiencies of proposed estimators, theoretical results are supported by empirical study and simulation study for which we have considered two populations. [ABSTRACT FROM AUTHOR]