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A class of ratio type estimators in double sampling using an auxiliary variable with some known population parameters


Toluwalase J. Akingbade and Fabian C. Okafor

YEAR: 2018


Many authors, to improve on the ratio (regression) estimator of the population mean of the study variable, have made use of some known population parameters of the auxiliary variable including the population mean of the auxiliary variable. In their work these authors have used the ratio (regression) – type estimator. In practical situations, the population mean of the auxiliary variable may not be known. In this paper therefore, we have suggested a class of regression - type ratio estimator when only the population mean of the auxiliary variable is unknown using double sampling procedure. The expression for the bias and the mean square error of the proposed estimators were derived and sub-members of the class of estimators were also identified. The conditions for which the proposed estimators perform better than the sample mean, classical ratio and existing ratio- type estimator in double sampling are derived. From the analysis, it was observed that the proposed estimators perform better than the existing estimators considered in this study.


Cochran, W. G. (1940). The estimation of the yields of the cereal experiments by sampling for the ratio of grain to total produce. Jour. Agri. Sci., 59, 1225 - 122 6.    

Cochran, W. G. (1942). Sampling theory when the sampling units are unequal sizes. J. Amer. Stat. Assoc., 37, 199-212. 

Cochran W.G. (1977). Sampling Techniques (3rd edition), John Wiley Eastern Limited, New York.  


Kadilar, C. and Cingi, H. (2004). Ratio estimators in simple random sampling. Applied Mathematics and Computation, 151(3), 893 - 902. 

Kadilar, C. and Cingi, H. (2006). An improvement in estimating the population mean by using  the correlation coefficient. Hacettepe Journal of Mathematics and Statistics, 35(1), 103 - 109. 

Malik, K. A. and Tailor, R. (2013). Ratio type estimator of population mean in double sampling. International  Journal of Advanced Mathematics and Statistics, 1(1), pp. 34 – 39. 


Murthy, M.N. (1964). Product method of estimation. Sankhya A, 26, 66 - 74. 

Raja, T. A., Subair, M., Maqbool, S. and Hakak, A. (2017). Enhancing the Mean Ratio Estimator for Estimating Population Mean Using Conventional Parameters. International Journal of  Mathematics and Statistics Invention (IJSM), 5(1), 58 - 61. Singh, D. and Chaudhary, F. S. (1986). Theory and analysis of sample survey designs. (1st ed.),  New Age International Publisher, India. 


Sisodia, B. V. S. and Dwivedi, V. K. (1981). A modified ratio estimator using coefficient of variation of auxiliary variable. Journal of the Indian Society of Agricultural Statistics, 33(1), 13 - 18. 


Singh, H. P. and Tailor, R. (2003). Use of known correlation coefficient in estimating the finite population means. Statistics in Transition, 6(4), 555 - 560. 

Subramani, J. & Kumarapandiyan, G. (2013). Estimation of Finite Population Mean Using Deciles of an Auxiliary Variable. Statistics in Transition-new series, 14( 1), pp. 75–88. 

Upadhyaya, L. N. and Singh, H. (1999).  Use of transformed auxiliary variable in estimating the finite population mean. Biometrical Journal, 41(5), 627 - 636. 

Yan, Z. and Tian, B. (2010). Ratio Method to the Mean Estimation Using Coefficient of Skewness of Auxiliary Variable. ICICA 2010, Part II, CCIS 106, pp. 103-110.


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