ID105 Prractice Exam
m3
The nextt set of questtions uses thee following set of data points
p
taken from
f
a discrrete populatioon:
1, 1, 2, 2, 2, 3, 3, 4, 4,
4 5, 6.
1) Makee a bar graph
h of this dataa using the blank graph provided.
p
2) Whatt is the mean
n of this distrribution?
a) 11
b) 3
c) 2.5
d) 2
5) W
What is the standard
s
devviation of thiis
s
sample
(not population) data set?
a 0.62
a)
b 2.6
b)
c 3.00
c)
d 1.61
d)
3) Whatt is the median of this distribution?
a) 11
b) 3
c) 2.5
d) 2
4) Whatt is the modee of this distrribution?
a) 11
b) 3
c) 2.5
d) 2
6) W
What is the variance
v
of this
t distributtion?
a 0.62
a)
b 2.6
b)
c 3.00
c)
d 1.61
d)
7) W
What is the skewness
s
off this
d
distribution?
?
a 0.62
a)
b 1.00
b)
c -0.81
c)
d 0.00
d)
Definitioons
8) A sett of classes or
o groups bassed on absollute mathematical value for which a meaningful zero
valuee exists (exam
mple: heightt, age):
a) A nominal sccale
b) An
A ordinal sccale
c) An
A interval sccale
d) A ratio scale
9) A meeasure of thee symmetry of
o the data abbout the meaan is:
a) The
T standard deviation
b) The
T median
c) The
T skewnesss
R. Gist
1 of
o 4
Ver B, Rev. 2
ID105 Exxam 3
The nextt set of questtions is takenn from the foollowing set of data whicch comes froom a populattion
which is continuously distributedd:
2 3.1, 3.8,, 3.8, 4.4, 4.55, 5.1, 5.3
1.3, 1.9, 2.1,
10) Draw
w a histogram
m of this dataa. Use the number
n
of claasses and thee class widthh that is show
wn
on the following blank graphh:
11) Whatt is the mean
n of this dataa?
a) 3.50
b) 3.80
c) 3.45
d) 3.53
14) What
W is the standard
s
devviation of thiis
s
sample
(not population) data set?
a 1.50
a)
b 1.55
b)
c 1.92
c)
d 1.39
d)
12) Whatt is the median of this daata?
a) 3.50
b) 3.80
c) 3.45
d) 3.53
15) What
W is the variance
v
of this
t data?
a 1.50
a)
b 1.55
b)
c 1.92
c)
d 1.39
d)
de of this data?
13) Whaat is the mod
a) 3.50
b) 3.80
c) 3.45
d) 3.53
e)
R. Gist
16) What
W is the skewness
s
off this data?
a 1.50
a)
b -4.10
b)
c 0.022
c)
d -1.75
d)
2 of
o 4
Ver B, Rev. 2
ID105 Exxam 3
The nextt set of questtions is basedd on the following norm
mal curve. Thhe curve below represennts
the resultts of a large population on
o a particullar exam. Thhe mean on the
t exam waas 70 (μ=70)).
The standdard deviatio
on on the exxam was 5 (σ
σ=5). Use thhe percentages given herre.
17) Chucck scores 80. What perceentage of alll
peoplle taking thiss test will sccore higher
than Chuck?
C
a) 0.5%
b) 2.5%
c) 16%
d) 844%
20) What
W is the highest
h
gradde someone else
e
c
could
have and
a still be inn the bottom
m
5
50%
of everryone taking the exam?
a 65
a)
b 70
b)
c 75
c)
d 80
d)
18) Usinng Chuck as an example,, you can
say thhat his gradee lies at the ______
_
perceentile.
a) 2.5 th
b) 16 th
c) 844 th
d) 97.5
9 th
21) What
W percenntage of all people
p
takingg the
e
exam
scoredd at least a 600?
a 2.5%
a)
b 16%
b)
c 84%
c)
d 97.5%
d)
19) Whatt is the lowest grade som
meone else
couldd have and sttill be in the top 16% of
all peeople taking the exam?
a) 60
b) 65
c) 70
d) 75
R. Gist
3 of
o 4
22) What
W percenntage of all people
p
takingg the
e
exam
scoredd between 600 and 80?
a 47.5%
a)
b 95%
b)
c 68%
c)
d 81.5%
d)
Ver B, Rev. 2
ID105 Exam 3
The next set of questions is based on normally distributed (fictional) data. The population
represents the household incomes in the state of Colorado. The average income was $50,000
(μ=50000). The standard deviation of incomes was $10000 (σ=10000). Using the z-score table
provided, answer the following:
23) What percentage of the population earned less
than $50000?
a) 40 %
b) 45 %
c) 50 %
d) 60 %
26) What percentage of the population earned less
than $35000?
a) 6.7 %
b) 19.2 %
c) 50 %
d) 75.6 %
24) What percentage of the population earned more
than $55000?
a) 10.4%
b) 30.8 %
c) 50 %
d) 68.8 %
27) What percentage of the population earned
between the average income and $55000?
a) 40 %
b) 30.8 %
c) 27.5 %
d) 19.2 %
25) If the population represented was 1.5 million
households, how many households earned more
than $55000?
a) 1 million
b) 0.84 million
c) 0.46 million
d) 0.15 million
28) What percentage of the population earned
between $35000 and $55000?
a) 6.7 %
b) 19.2 %
c) 50 %
d) 62.5 %
____________________________________________________________________________
Z-Score Table
(A)
z-score
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
R. Gist
(B)
Area between z
and the mean
0.000
0.040
0.079
0.118
0.155
0.192
0.226
0.258
0.288
0.316
0.341
0.364
0.385
0.403
0.419
0.433
(C)
Area beyond
z
0.500
0.460
0.421
0.382
0.345
0.309
0.274
0.242
0.212
0.184
0.159
0.136
0.115
0.097
0.081
0.067
(A)
z-score
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
4 of 4
(B)
Area between z and
the mean
0.445
0.455
0.464
0.471
0.477
0.482
0.486
0.489
0.492
0.494
0.495
0.496
0.497
0.498
0.499
(C)
Area
beyond z
0.055
0.045
0.036
0.029
0.023
0.018
0.014
0.011
0.008
0.006
0.005
0.004
0.003
0.002
0.001
Ver B, Rev. 2