TWO-PHASE SAMPLE SIZE ESTIMATION WITH PRE-ASSIGNED VARIANCE UNDER NORMALITY ASSUMPTION

Document Type: Regular Paper

Authors

1 Department of Mathematics, Statistics and Physics, Qatar University, Doha, Qatar Department of Mathematical Sciences, Isfahan University of Technology, Isfahan, I. R. of Iran

2 3RTI International, Research Triangle Park, North Carolina, USA

3 School of Mathematics and Statistics, Carleton University, Ottawa, Canada

Abstract

We develop a two phase sampling procedure to determine the sample size necessary to estimate
the population mean of a normally distributed random variable and show that the resulting estimator has preassigned variance and is unbiased under a regular condition. We present a necessary and sufficient condition under which the final sample mean is an unbiased estimator for the population mean.

Keywords