Sampling survey to the total population of Heshun county in Shanxi province in year 1998
Implementation steps:
- Calculate the total optimal sample size n according to the known accuracy requirement;
- Calculate the sample size nh of each layer h according to the proportion distribution /optimal distribution design of the sample size;
- Randomly extract nh samples from layer h respectively with computer pseudo-random number;
- Estimate the total population according to the investigated population of sampling sites.
Calculate:
Sample size according to the optimal distribution design:
- Total optimal sample size:
- Sample size of each layer:
- Estimate the total population of Heshun county according to the 57 sampling sites:
The total optimal sample size is 46 in fact
The sampling size after extending 10% is 57
Sampling accuracy:
of each layer
；
Population size
N;
Each layer variance 
；
Each layer cost 
；
Given variance
V
of estimation;
Layer mean
；
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
).