26.當總體內(nèi)部差異比較大時，比較適合的抽樣組織方式是(      )

A.簡單隨機抽樣                                               B.整群抽樣

C.分層抽樣                                                      D.純隨機抽樣

27.在用樣本指標推斷總體指標時，可靠程度越高則(      )

A.誤差范圍越小                                               B.誤差范圍越大

C.抽樣平均誤差越小                                        D.抽樣平均誤差越大

28.下列相對數(shù)中，可以用有名數(shù)表示的有(      )

A.計劃完成相對數(shù)                                           B.結構相對數(shù)

C.強度相對數(shù)                                                  D.動態(tài)相對數(shù)

29.某產(chǎn)品合格率為90%，則成數(shù)標準差是(      )

A.10%                                                             B.90%

C.9%                                                               D.30%

30.統(tǒng)計指數(shù)按其范圍不同，可分為(      )

A.個體指數(shù)和綜合指數(shù)                                    B.簡單指數(shù)和綜合指數(shù)

C.數(shù)量指數(shù)和質量指數(shù)                                    D.簡單指數(shù)和總指數(shù)