RATIO-CUM-PRODUCT ESTIMATORS USING TWO AUXILIARY VARIABLES IN RANKED SET SAMPLING

摘要

Many forms of ranked set samples have been introduced recently for estimating the population mean and other parameters. In this paper, we proposed two ratio-cum-product estimators of finite population mean using known coefficient of variations and co-efficient of kurtosis of auxiliary characters in Ranked Set Sampling (RSS). It has been shown that this method is highly beneficial to the estimation based on Simple Random Sampling (SRS). The bias and mean squared error of the proposed estimators with large sample approximation are derived. Theoretically, it is shown that these suggested estimators are more efficient than the ratio-cum-product estimators in simple random sampling.