分层取样;定样;
Methods An equal-sized stratified multi-stage randomly sampling design was applied to obtain three provincially representative sample groups consisted of 720 Guangdong residents each, aged at 12,35-44 and 65-74 years old respectively, with a gender ratio of half to half.
方法采用多阶段分层等容量随机抽样的方法,抽取广东省12岁、35~44岁、65~74岁城乡常住人口各720人,男女各半。
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