Method:254 people aged 51~75 with twostagesampling were investigated by using multifactor analyses.
方法：采用二阶段抽样法对254名51～75岁居民用多因素分析法进行了调查分析。
2
This paper studies the second stagesampling methods used in the twostagesampling survey for waterway transportation volume.
研究了采用二阶抽样对水路运输量进行抽样调查时的第二阶抽样方法。
3
The present balanced two-layer sample rotation system is applicable only to the monthly survey with two-stage sample designs and with small primary sampling units.