I want to know a statistical package that can solve problems in sampling such as carrying out sampling, computing mean square errors of estimators, etc
there are some statistical packages that help with survey sampling, but it depends primarily on which software you use. If you, as I do, use R, then there are some choices, such as the package "sampling". Otherwise, if you prefer a software like SAS, there is a number of procedures that you might want to use, see on http://support.sas.com/rnd/app/da/new/dasurvey.html