A.傳染病報(bào)告卡B.門診病歷C.統(tǒng)計(jì)報(bào)表D.問卷調(diào)查
A.1.64B.1.96C.2.33D.2.58
A.離散趨勢(shì)B.集中趨勢(shì)C.對(duì)稱趨勢(shì)D.抽樣誤差