improved ratio estimators of variance based on robust measures

This study developed some new estimators for estimating population variance by utilizing available information on midrange and an interdecile range of auxiliary variables. a general class of estimators was also suggested. the derivations of the bias and the mean squared error were presented. conditions were determined to verify the efficiency of the proposed estimators over existing estimators considered in this study. an empirical study was also provided for illustration and verification. moreover, a robust study was carried out to evaluate the performance of the proposed estimators in comparison to existing estimators in case of extreme values. according to the theoretical and empirical research, it was found that the suggested estimators performed more efficiently than the existing estimators.