Estimation of population coefficient of variation in simple and stratified random sampling under two-phase sampling scheme when using two auxiliary variables |
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Authors: | Javid Shabbir Sat Gupta |
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Institution: | 1. Department of Statistics, Quaid-i-Azam University, Islamabad, Pakistan;2. Department of Mathematics and Statistics, The University of North Carolina at Greensboro, Greensboro, NC, USA |
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Abstract: | We propose an improved class of exponential ratio type estimators for coefficient of variation (CV) of a finite population in simple and stratified random sampling using two auxiliary variables under two-phase sampling scheme. We examine the properties of the proposed estimators based on first order of approximation. The proposed class of estimators is more efficient than the usual sample CV estimator, ratio estimator, exponential ratio estimator, usual difference estimator and modified difference type estimator. We also use real data sets for numerical comparisons. |
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Keywords: | Coefficient of variation Efficiency Stratification Bias Mean square errors |
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