On estimation of ratio of population means in survey sampling when some observations are missing

[[abstract]]This paper aimed at the improved estimation of ratio of population means inthe presence of some observations are missing. Two estimators are proposed and their properties of relative bias as well as mean square error are studied.Also, a comparison of the proposed estimators with reespect to the four types of ratio estimators, suggested by Toutenburg and Srivastava [3], is given.[[notice]]補正完畢[[journaltype]]國外[[incitationindex]]EI[[booktype]]紙本[[countrycodes]]IN