The purpose of writing this book is to suggest some improved estimators

using auxiliary information in sampling schemes like simple random sampling,

systematic sampling and stratified random sampling.

This volume is a collection of five papers, written by nine co-authors

(listed in the order of the papers): Rajesh Singh, Mukesh Kumar, Manoj Kr.

Chaudhary, Cem Kadilar, Prayas Sharma, Florentin Smarandache, Anil

Prajapati, Hemant Verma, and Viplav Kr. Singh.

In first paper dual to ratio-cum-product estimator is suggested and its

properties are studied. In second paper an exponential ratio-product type

estimator in stratified random sampling is proposed and its properties are

studied under second order approximation. In third paper some estimators are

proposed in two-phase sampling and their properties are studied in the

presence of non-response.

In fourth chapter a family of median based estimator is proposed in

simple random sampling. In fifth paper some difference type estimators are

suggested in simple random sampling and stratified random sampling and their

properties are studied in presence of measurement error.