Estimate the total population of Heshun county in year 1998 according to the population data of 98 sample villages in the sampling investigation of Heshun county
Implementation steps:
- The estimated population mean of the knowledge layer are fed back to the administrative layer (town);
- The estimated accuracy of knowledge layer are fed back to the administrative layer (town).
Calculate:
- The estimated total population according to 98 sample village population:
- Estimate the mean and variance of reporting unit according to the knowledge layer (the reporting units are 10 towns of Heshun county)
Due to the size and distribution of the site, the variance of individual knowledge layer cann't be computed, the variance of some reporting unit is 0.
；
Layer weight 
(It is the proportion that the administrative village size of each town account for the total size of the administrative village of Heshun county) ；
Population mean 
；
Variance 
(the variance of the estimation of the total population mean 
) .