Scientific Research Publishing

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53676#.VM8uXyzQrzE Author(s)     Aloy Chijioke Onyeka , Chinyeaka Hostensia Izunobi , Iheanyi Sylvester Iwueze Affiliation(s) Department of Statistics, Federal University of Technology, Owerri, Nigeria . ABSTRACT The study proposes, along the line of [1], six separate-type estimators for estimating the population ratio of two variables in post-stratified sampling, using variable transformation. Properties of the proposed estimators were obtained up to first order approximations, both for achieved sample configurations (conditional argument) and over repeated samples of fixed size n (unconditional argument). Efficiency conditions, under which the proposed separate-type estimators would perform better than the associated customary separate-type estimators in terms of having smaller mean squared errors, were obtained. Furthermore, conditions under w...

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53360#.VMBeeSzQrzE Author(s)    Aloy Chijioke Onyeka , Chinyeaka Hostensia Izunobi , Iheanyi Sylvester Iwueze Affiliation(s) Department of Statistics, Federal University of Technology, Owerri, Nigeria . ABSTRACT Extending the work carried out by [1], this paper proposes six combined-type estimators of population ratio of two variables in post-stratified sampling scheme, using variable transformation. Properties of the proposed estimators were obtained up to first order approximations,( on <span "="">– 1 ), both for achieved sample configurations (conditional argument) and over repeated samples of fixed size n (unconditional argument). Efficiency conditions were obtained. Under these conditions the proposed combined-type estimators would perform better than the associated customary combined-type estimator. Furthermore, optimum estimators among the...

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53360#.VL3P6SzQrzE Author(s)    Aloy Chijioke Onyeka , Chinyeaka Hostensia Izunobi , Iheanyi Sylvester Iwueze Affiliation(s) Department of Statistics, Federal University of Technology, Owerri, Nigeria . ABSTRACT Extending the work carried out by [1], this paper proposes six combined-type estimators of population ratio of two variables in post-stratified sampling scheme, using variable transformation. Properties of the proposed estimators were obtained up to first order approximations,( on <span "="">–1 ), both for achieved sample configurations (conditional argument) and over repeated samples of fixed size n (unconditional argument). Efficiency conditions were obtained. Under these conditions the proposed combined-type estimators would perform better than the associated customary combined-type estimator. Furthermore, optimum estimators among the ...