A FAMILY OF FACTOR-TYPE ESTIMATORS FOR ESTIMATION OF POPULATION VARIANCE
In the present paper, we have proposed factor-type ratio estimator using known values of some population parameters of the auxiliary variable to estimate the population variance of the study variable. The expressions for the bias and mean squared error (m.s.e.) of the proposed estimator have been derived up to first order of approximation. The suggested estimator is bias controlled and gives choices for optimal mean squared error. A comparison has been made with some well-known estimators and it is shown that the proposed estimator is better than some other existing estimators.