PAKISTAN JOURNAL OF STATISTICS AND OPERATION RESEARCH, cilt.15, sa.4, ss.1037-1050, 2019 (ESCI)
In this paper we attempt the problem of estimation of the sum of mean and the change of mean in mail surveys. This problem is conducted for current occasion in the context of cluster sampling over sampling on two successive occasions. The sampling units are clusters and the observations on the first occasion are regarded as ancillary information for the observations on the second or current occasion.