出版社：Dep. of Statistical Sciences "Paolo Fortunati", Università di Bologna
摘要：This paper advocates the problem of estimating the population mean of the study variable y using the information on two auxiliary variables x and z. We have suggested the family of chain ratio exponential type estimators in two-phase (or double) sampling. The bias and mean squared error (MSE) are obtained upto the first order of approximation. The suggested class of estimators is more efficient than the two-phase ratio estimator, Chand’s (1975) chain-type ratio estimator and Singh and Vishwakarma’s (2007) estimator in two-phase (or double) sampling. An empirical study is given to justify the superiority of the proposed estimator.
关键词：study variable;auxiliary variables;chain-type ratio estimator;bias and mean squared error
