Cost Issue in Estimation of Proportion in a Finite Population Divided Among Two Strata

The problem of estimation of the proportion of units with a given attribute in a~finite population is considered. From the population a sample is drawn due to the simple random sampling without replacement. There are limited funds for conducting survey sample. Suppose that the population is divided into two strata. The question now arises: how should sample sizes be chosen from each strata to obtain the best estimation of proportion without exceeding the budget planned. In the paper it is shown, that with the appropriate sample allocation the variance of the stratified estimator may be reduced up to 30% off of the standard, unstratified estimator.