Determination of requisite sample size for surveys

The sample sizes required to estimate population mean with per-specified margins of error were empirically determined. As expected, it was observed that the sample size required depend upon i) the population standard deviation; and ii) the permissible margin of error. More the population standard deviation, more will be the required sample size; and more the permissible margin of error, less the sample size. Also, the formulae for the estimation of required sample size as proposed by Sukhatme and Sukhatme (1970) and Murthy (1977) were found to be valid for the actual data on farmer's fields.