重复抽样与不重复抽样相比，其样本均值抽样分布的标准差（ ）。[西安交大2007研]

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='30462' and id < 2461246 and id<>'2461246' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='30462' and id > 2461246 and id<>'2461246' order by id asc limit 5