AP Statistics
Quiz2.lA
Name:
a midwesternelementaryschooltook a "self-concept"testthat
themselves.Higherscoresindicatemorepositiveself-concepts.A
histogramand somesurnmarystatisticsfrom Minitab for thesestudents'self-conceptscoresaregiven
below.
of 78 third-gade
n
Iro
a
o
'5
t
*
ir".-;
DescriptiveStatistics: SelfConcept
Variable
SelfConc
N
78
Variable
SelfConc
Minimum
Maximum
20.00
80.00
Median
59.50
TrMean
57.81
Q1
51.00
Q3
65.25
iltp"i--..
SE Mean
1.41
1. Draw an appropriatedensitycurvefor summarizingthe histogramon the graphabove. How would
you describethe shapeof this densitycurve?
A)\trA,sL
U-4-L
2. Onestudentin the grouphad a self-conceptscoreof 62. Thirty-four studentshad self-concept
scoreshigherthan 62. Describethe locationof this valuewithin the distributionusingraw data,
percentiles,andstandardizedvalues(z-scores).
t/ttvt
L--
oJ ( tL'
4Ll
F
, 5b.4
h
.An.
&=5(a,4h\yWcyft,q
bL - qlo.qv
tz.Ll I
-+
a4ou^L p.Ll l S}1,r(
".o{
6rl-tv1'
a,boq I1^,L nt-tt,vy
"1lrwS
Whatis a "typical" self-conceptscorefor a third-graderin this group? Justify your answer.
51.5 +
Chapter2
gSt 4W rvu}-t'a,a,4 ^ 6?U.lee(oL,'sl-,r,W-aa
h Al4sr,tr\a+1q cn&,r bru*sa ,l ;s rtt-oy4
y"c8t6+a*t
*o u-WLnq.
obs/ yyufivns
Quiz2.lA
Quiz2.2A
AP Statistics
Name:
1. A studyof elite distancenulnersfound a meanbody weight of 63.1 kilograms(kg), with a standard
deviationof 4.8 kg.
(a) Assumingthat the distribution of weightsis Normal,makean accuratesketchof the weight
distibution with the horizontalaxis markedin kilograms.
rt(os.l
,,t.r)
(b) Usethe 68-95-99.7rule to find theproportionof nrnnerswhosebody weightis between48.7
and67.9kg. Showyour method.
.1)
tl.5
?,551'
-9
-(t2.5*2.b5) = t3.86%
10t.1
tl
(c) Calculateandinterpretthe 45th percentileof the runners'body weight distribution.
15n (v, er,-t,lt :
L=
L- Y- ll
f
-0, l3
X'- bZ,q1AVq,
d
t.-{,.+
lfr^rLtr.l-u'5
_o.(3= *-Q?.1
'l'V
2. UseTableA to find the proportionof observationsfrom a standardNormal distributionthat
satisfies-1.51 < Z < 0.84. SketchtheNormalcurveandshadethe areaunderthe curvethat is the
answerto the question.
ru
0,-1q15- g,ob# =
AJ3,to
- l,Sl o 0-Y'l
Give anexampleof a quantitativevariablethatdoesnothavea Normaldishibution. Justiff your
answer.
.-/ttrn'a y; eu-
*h-euu(
r,4lrd
t)
Chapter2
Quiz2.2A