6.相對指標(biāo)數(shù)值的表現(xiàn)形式是(　　　)

A.無名數(shù)                                                        B.有名數(shù)

C.復(fù)名數(shù)                                                        D.有名數(shù)和無名數(shù)

7.在假設(shè)檢驗(yàn)中，由于抽樣偶然性，拒絕了實(shí)際上成立的原假設(shè)H₀，則(　　　)

A.犯第Ⅰ類錯(cuò)誤                                              B.犯第Ⅱ類錯(cuò)誤

C.推斷正確                                                     D.A、B都有可能

8.如果一組數(shù)據(jù)中有一項(xiàng)為零，則不能計(jì)算(　　　)

A.算術(shù)平均數(shù)                                                 B.調(diào)和平均數(shù)

C.眾數(shù)                                                            D.中位數(shù)

9.變量Y之間的線性相關(guān)系數(shù)為0，說明這兩個(gè)變量之間是(　　　)

A.負(fù)相關(guān)關(guān)系                                                 B.完全相關(guān)關(guān)系   

C.不存在線性相關(guān)                                          D.完全不相關(guān)

10.下面屬于非隨機(jī)抽樣的抽樣方式有(　　　)

A.系統(tǒng)抽樣                                                     B.整群抽樣   

C.等距抽樣                                                     D.滾雪球抽樣