Abstract:
In this article we study the ratio estimator, regression estimator and ratio regression estimator using two auxiliary variables in simple random sampling, which is a review from parts of an article Abu-Dayyeh et al. [Applied Mathematics and Computation. 162:
901-908]. The estimators are biased estimators. Then mean square error of each
estimator is determined. The estimator with the smallest mean square error is the most
efficient estimator. An example is given at the end of discussion.