EFFICIENT CLASSES OF RATIO-TYPE ESTIMATORS OF POPULATION MEAN UNDER STRATIFIED MEDIAN RANKED SET SAMPLING.

In this paper, we propose two efficient classes of ratio-type estimators for estimating the finite population mean (Y) under stratified median ranked set sampling (StMRSS) using the known auxiliary information. The biases and mean squared errors (MSEs) of the proposed classes of ratio-type estimators are derived upto first order of approximation. The proposed estimators are compared with some competitor estimators. It is demonstrated through simulation study that the proposed ratio-type estimators based on t S MRSS are more efficient than the corresponding estimators in stratified ranked set sampling (StMRSS) given by Mandowara and Mehta [13]. [ABSTRACT FROM AUTHOR]