20.交替標(biāo)志(成數(shù))方差的最大值為

A.1                                                                  B.0.5     

C.0.25                                                              D.0

21.平均增長速度的計(jì)算方法是

A.                                                        B.

C.平均增長速度=平均發(fā)展速度-100%              D.

22.累積增長量等于相應(yīng)各時(shí)期的逐期增長量

A.之差                                                             B.之商  

C.之和                                                             D.之積

23.當(dāng)總體X服從正態(tài)分布N（μ,σ2）時(shí)，根據(jù)______知道，樣本均值也服從正態(tài)分布。

A.中心極限定理                                               B.正態(tài)分布的性質(zhì)

C.抽樣分布                                                      D.統(tǒng)計(jì)推斷

24.統(tǒng)計(jì)指數(shù)按構(gòu)成因素不同，可分為

A.個(gè)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(zhì)量指數(shù)                                    D.簡單指數(shù)和總指數(shù)

25.兩變量的相關(guān)系數(shù)為－0.8，說明

A.兩變量不相關(guān)                                               B.兩變量負(fù)相關(guān)

C.兩變量完全相關(guān)                                           D.兩變量完全正相關(guān)

26.編制質(zhì)量指標(biāo)綜合指數(shù)，其同度量因素一般固定在

A.基期                                                             B.報(bào)告期      

C.計(jì)劃期                                                         D.任意時(shí)期

27.在用回歸方程進(jìn)行估計(jì)推算時(shí)，

A.只能用依變量推算自變量                             B.只能用自變量推算依變量

C.不須考慮因變量和自變量問題                      D.自變量和依變量可相互推算

28.對某市居民收支情況進(jìn)行調(diào)查，下列哪種方法不能用？

A．抽樣調(diào)查                                                   B.重點(diǎn)調(diào)查  

C.典型調(diào)查                                                      D.全面調(diào)查

29.如果采用六項(xiàng)移動(dòng)平均修勻時(shí)間數(shù)列，那么所得修勻數(shù)列比原數(shù)列首尾各少

A.一項(xiàng)數(shù)值                                                      B.二項(xiàng)數(shù)值  

C.三項(xiàng)數(shù)值                                                      D.四項(xiàng)數(shù)值