Sampling survey to the total population of Heshun county in Shanxi province in year 1998
Implementation steps:
- Calculate the optimal sample size n according to the known accuracy requirement;
- Randomly extract n sample villages from 326 administrative villages with computer pseudo-random number;
- Estimate the total population according to the sampling sites.
Calculate:
Estimate the average population of each village firstly, then the mean multiply the village size, the result is the total population of Heshun county.
- The average absolute error of each village population is
Theoretically suggest that the total sample size is 198
Suggest that the sampling size after extending 10% is 218- Estimate the total population of Heshun county according to the 218 sampling sites:
Sample variance:
Sampling accuracy:
of each village population
；
Confidence level 
；
All the administrative village size
N
in the re search areas
;
Sample value
；
Sample mean 
.