keywords: Efficiency, finite population, mean squared error, ratio estimator, variance
This paper is basically aimed at suggesting two modified ratio-cum-product estimators having two auxiliary variables, under the linear systematic sampling. These suggested ratio-cum-product modified estimators under the two-phase sampling scheme were suggested using linear transformation technique, the biases and mean squared errors (MSEs) of the corresponding modified estimators under cases I and II were derived and established (where Case I refers to the case whereby the second sample is drawn from the first sample and Case II refers to the case whereby the second sample is drawn from the main population under study), the efficiency conditions under which the two modified estimators would be more efficient than relative existing ones were derived and established and the relative efficiency of these modified estimators were empirically determined and established using five real life data sets which were obtained from various sources. From the results of the empirical study using real life data sets, it was concluded that the suggested modified estimators in this study demonstrated high relative efficiency over existing related estimators.