magoosh-1简单数学题目统计.pdfVIP

magoosh题目--统计

1Easy

1.Iftheaverage(arithmeticmean)ofx,yand15is9,andtheaverageofx,2yand2is

7,theny=

A.5

B.6

C.7

D.8

E.9

2.Inacertainclass,xstudentsare10yearsold,andtheremainingystudentsare11

yearsold.Whatistheaverage(arithmeticmean)ageofallstudentsintheclass?

xy

A.

21

10x11y

B.

21

y

C.110x

xy

y

D.110x

xy

10x11y

E.

xy

3.Theaverage(arithmeticmean)oftwonumbersis4x.Ifoneofthenumbersisy,

thenthevalueoftheothernumberis

A.x-4y

B.4x+4y

C.8x-4y

D.4y-8x

E.8x-y

4.Whichofthefollowingsetsofnumbershasthegreateststandarddeviation?

A.10,11,12

B.-3,-4,-5

C.-2,0,2

D.5.1,5.2,5.3

E.20,22,22.5

5.Iftheaverage(arithmeticmean)of24consecutiveoddintegersis48,whatisthe

medianofthe24numbers?

A.36

B.47

C.48

D.49

E.72

6.

Tenstudentswroteatest,andthedistributionofscoresisshownonthefrequency

table.Iftheaverage(arithmeticmean)scoreis62,whatisthevalueofx?

A.62

B.65