  Chakrabarty, Khoshnevisan, Sahai and Ray, Solanki suggested some estimators
to estimate unknown population mean of the study variable. These authors
discussed the estimators along with their first order biases and mean square
errors(MSEs). In this paper, we have tried to found out the second order biases
and mean square errors of some estimators using information on auxiliary
attribute. We have compared the performance of the estimators with the help of
a numerical illustration.
