A.組中值B.樣本容量C.組次數(shù)D.平均數(shù)
A.降低誤差B.估計(jì)誤差C.便于試驗(yàn)操作D.消除誤差
A.數(shù)字特征B.統(tǒng)計(jì)量C.觀察值D.樣本數(shù)