Improved Estimator of Population Variance using Measure of Dispersion of Auxiliary Variable MUHAMMAD KHALIL, MUHAMMAD ALI, USMAN SHAHZAD*, MUHAMMAD HANIF and NASIR JAMAL Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan. Abstract This research study is designed to obtain a more precise class of estimators of a population variance by taking advantage of relation between auxiliary variable and study variable. Here a class of new modified ratio type estimators of population variance by using coefficient of variation (CV), standard deviation, mean and median of auxiliary variable. Further empirical study is made to compare bias and mean square error (MSE) of proposed estimators with the existing estimators. Expressions for bias and MSE are obtained. Few secondary data sets are used to check the efficiency of proposed estimators of population variance. Article History Received: 29 March 2018 Accepted: 14 June 2018 Keywords: Bias, Mean Squared Error, Natural Populations, Simple Random Sampling. CONTACT Usman Shahzad usman.stat@yahoo.com Pir Mehr Ali Shah Arid Agriculture University Rawalpindi, Pakistan. © 2017 The Author(s). Published by Exclusive Publishers This is an Open Access article licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (https://creativecommons.org/licenses/by-nc-sa/4.0/), which permits unrestricted NonCommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Oriental Journal of Physical Sciences www.orientjphysicalsciences.org ISSN: 2456-799X, Vol.03, No.(1) 2018, Pg. 33-39 Introduction In our everyday life variations are available all over the place. It is the idea of law that people or no two things are precisely same. For example, an agriculturist needs a sufficient comprehension of the varieties in climatic factors particularly from place to place (or time to time) to have the capacity to anticipate when, how and where to plant his yield. For consistent learning of the level of varieties in individuals' response a maker need to decrease or increase cost of his item, or make strides the nature of his item. A doctor needs a full comprehension of varieties in the body temperature, level of human circulatory strain and heartbeat rate for full remedy. In this article we estimate one of the measure of variation which is known as variance. The following Notations are used throughout this paper. “N” : Size of Population “n” : Size of Sample γ฀: 1/n Y : Variate of interest X : Supplementary variate