6.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

7.受極值影響最大的是(      )

A.算術(shù)平均數(shù)                                                  B.幾何平均數(shù)

C.調(diào)和平均數(shù)                                                  D.四分位數(shù)

8.在研究對(duì)象的總體中，選取其中的重點(diǎn)單位進(jìn)行調(diào)查。這種方法是(      )

A.普查                                                             B.重點(diǎn)調(diào)查

C.典型調(diào)查                                                      D.抽樣調(diào)查

9.累計(jì)頻數(shù)分布曲線一般都呈(      )

A.鐘型曲線                                                      B.U型曲線

C.J型曲線                                                       D.邏輯斯蒂曲線

10.三個(gè)流水作業(yè)的生產(chǎn)車間的廢品率分別為5%，2%，4%，則這三個(gè)車間的平均廢品率為(      )

A.3.42%                                                           B.3.675%

C.3.667%                                                         D.3.158%

11.公式 適用來(lái)計(jì)算(      )

A.未分組資料的算術(shù)平均數(shù)                             B.分組資料的算術(shù)平均數(shù)

C.未分組資料的幾何平均數(shù)                             D.分組資料的幾何平均數(shù)

12.第五次人口普查我國(guó)出生人口性別比為116.86。這個(gè)相對(duì)數(shù)是(      )

A.百分?jǐn)?shù)                                                         B.比率

C.成數(shù)                                                             D.比重

13.下列各項(xiàng)中屬于時(shí)期指標(biāo)的是(      )

A.人口數(shù)                                                         B.商品庫(kù)存量

C.商品銷售量                                                  D.企業(yè)設(shè)備臺(tái)數(shù)

14.劃分連續(xù)型變量的組限時(shí)，相鄰組的組限必須(      )

A.交叉                                                             B.不等

C.重疊                                                             D.間斷

15.有意識(shí)地選擇若干企業(yè)的產(chǎn)值，來(lái)估算該地區(qū)的產(chǎn)值，這是(      )

A.普查                                                             B.典型調(diào)查

C.抽樣調(diào)查                                                      D.重點(diǎn)調(diào)查