6.從某生產(chǎn)線上每隔55分鐘抽取5分鐘的產(chǎn)品進(jìn)行檢驗(yàn)，這種抽樣方式屬于(      )

A.等距抽樣                                                 B.類型抽樣

C.整群抽樣                                                 D.簡(jiǎn)單隨機(jī)抽樣

7.數(shù)字間可以組成一個(gè)有意義的比率，可以做除法運(yùn)算。這種測(cè)量水平是(      )

A.定類尺度                                                 B.定量尺度

C.定比尺度                                                 D.定序尺度

8.人口抽樣調(diào)查的調(diào)查單位是(      )

A.全部人口                                                 B.全部人口數(shù)   

C.一部分人                                                 D.每戶家庭

9.在分組時(shí)，身高164cm應(yīng)歸入下列哪一組？(      )

A.160~164cm                                              B.164~168cm

C.160~164cm或164~168cm                        D.另立一組

10.符號(hào)P_i= 代表的含義是(      )

A.變量值                                                     B.單位數(shù)   

C.頻數(shù)                                                        D.頻率