GENERALIZED ESTIMATOR FOR ESTIMATING POPULATION MEAN UNDER TWO STAGE SAMPLING.

Koyuncu and Kadilar (2009) proposed a family of ratio-type estimators for population mean using auxiliary information in simple random sampling. Srivastava and Garg (2009) proposed a general class of ratio estimator for estimating population mean using auxiliary variablein two-stage sampling. In this paper, motivated by Srivastava and Garg (2009) and Koyuncu and Kadilar (2009) we have proposed a general class of estimators for population mean for three different cases in two-stage sampling design. The mean square error (MSE) and bias expressions have been obtained in a general form up to the first order of approximation for the three cases. It has also been shown that for each of the three cases in two-stage sampling, minimum MSE of this class is asymptotical equal to the MSE of regression estimator. An empirical study has also been carried out, in order to demonstrate the performance of proposed general class of estimators for three cases in two-stage sampling design. [ABSTRACT FROM AUTHOR]