Two classes of estimators in two different situations of (i) unknown and (ii) known variance ([sigma]2), for estimating the population mean ([mu]) of symmetrical populations have been proposed. The general expressions of bias and mean squared error, of which the bias and mean squared error of...

Srivastava and Jhajj (1981) proposed a class of estimators for population mean of a character using auxiliary information and optimum values involving unknown parameters. From the practical point of view, their results have very little utility. In view of practical utility, we propose a class of...

A generalized estimator representing a class of estimators is proposed for the estimation of regression coefficients in the linear regression model when the error components have the joint multivariate Student-t distribution. Approximate expressions for the bias and the risk of the proposed...