NEW RATIO ESTIMATORS OF THE MEAN USING SIMPLE RANDOM SAMPLING AND RANKED SET SAMPLING METHODS

Abstract

In this paper, modified ratio estimators of the population mean of the variable of interest are suggested involving the first or third quartiles of an auxiliary variable that is correlated with the variable of interest. The newly suggested estimators are investigated under simple random sampling (SRS) and ranked set sampling (RSS) methods. It is found that these estimators are approximately unbiased and the RSS estimators are more efficient than those based on SRS method for the same quartile and sample size. Also, it is found that, when the two quartiles are compared, estimators based on the third quartile are more efficient than the first quartile