random population

Reproductive women were selected by random sampling from the sub-population who had a temporary residence permit or permanent residents in townships in 4 project sites.

通过随机抽样方法在四个项目点各选择2个乡镇作为研究现场，以抽到的乡镇内办理了暂住证或常住居民为子总体，抽取符合条件的育龄妇女。

Methods Different target population were chosen at random and investigated with questionnaire. The data were analyzed.

方法采取随机抽样方法,对不同层次目标人群进行问卷调查并统计分析.

Methods Used blood-type-population-genetics method, 12000 blood donors from the Han nationality were enrolled into the investigation at random, and the distribution of ABO, Rh blood type antigen and their gene frequency were analyzed.

方法用血型群体遗传学研究方法，随机选择新乡市地区无血缘关系的汉族无偿献血者12000名，进行ABO、Rh血型系统的表现型及基因频率分布调查分析。

( statistics) law stating that a large number of items taken at random from a population will ( on the average) have the population statistics.

（统计）从总体中随机抽取大量样本在平均情况下都能呈现总体的统计数。

In a simple random sampling, the sample mean is an unbiased estimate of the population mean.

在简单随机抽样中, 样本均值是总体均值的无偏估计.