样本含量分别为n1和n2的两样本率分别为p1和p2，其合计率pc的计算公式

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='10706' and id < 854655 and id<>'854655' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='10706' and id > 854655 and id<>'854655' order by id asc limit 5