Department of Mathematics and Statistics  Dr. Sir Hari Singh Gour University Sagar, M.P. (INDIA

In this paper we have suggested a family of ratio-cum product estimator when the population coefficient of variation (Cx) alongwith population means (X ) of the auxiliary variable x is known in advance. Its bias and variance to the first degree of approximation are obtained. For an appropriate weight ‘w’ and a good range of -values, it is shown that the suggested estimator is more efficient than the set of estimators viz. usual unbiased estimator, usual ratio and product estimators, Sisodia and Dwivedi’s5 estimator, Bansal and Singh’s1 estimator, Chakraborty’s2 type estimator, Vos’s8 type estimator and Sahai and Ray4 type estimator, some of which are in fact particular members of it.