Download answers - Parkway C-2

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Determine whether each statement is true or false. If the
statement is false, explain why.
1. When the mean is computeq for individual data, all
values in the data set are used. Tr"" e.....
2. The mean cannot be found for grouped data when there
is an open class. Tt'~
3. A single, extremely large value can affect the median
more than the mean. F oJ £ e..
4. One-half of all the data values will fall above the mode,
and one-half will fall below the mode. Fo...l se..
5. In a data set, the mode will always be unique. FcJse,;
6. The range and midrange are both measures
of variation. FQ.f Se..
7. One disadvantage of the median is that it is
not unique. 1=0..,[Se...
8. The mode and midrange are both measures
of variation. FalSe.
9. If a person's score on an exam corresponds to the
75th percentile, then that person obtained 75 correct
answers out of 100 questions. Po.../Se...
Select the best answer.
10. What is the value of the mode when all values in the
data set are different?
a.
b.
(£)
d.
0
1
a. 50%
(f)
68%
c. 95%
d. 99.7%
Complete these statements with the best answer.
16. A measure obtained from sample data is called
a(n)
. S-to.-T'IS-t'l c....
17. Generally, Greek letters are used to represent
, and Roman letters are used to represent
. PQ..ra..fY1~T~rs
~ "TCl,.,.;st
;c.~
18. The positive square root of the varia~ce is called
the
. S-i-Q.f\d.o"rd.
ck.u
\Q,t~~t'\
19. The symbol for the population standard deviation is
C!Y
20. When the sum of the lowest data value and the highest
data value is divided by 2, the measure is called
. I'Y) 'Id. ~~f'! ~Q...
21. If the mode is to the left of the median and the mean is
to the right of the median, then the distribution is
p
OS :;-: v~\ Yr.
skewed.
22. An extremely high or extremely low datll value is called
There is no mode.
It cannot be determined unless the data values are
given.
11. When data are categorized as, for example, places of
residence (rural, suburban, urban), the most appropriate
measure of central tendency is the
a. Mean
b. Median
c. A coefficientof variation
Azscore
15. When a distributionis bell-shaped,approximatelywhat
percentageof data values will fall within 1 standard
deviationof the mean?
@
(D Mode
d. Midrange
12. p 50correspondsto a.. o "C"-I b
a. Q2
b. D5
c. IQR
d. Midrange
13. Which is not part of the five-numbersummary?
a. QI and Q3
C£) The mean
c. The median
d. The,smallestand the largestdata values
14. A statisticthat tells the numberof standarddeviationsa
data value is above or below the mean is called
a
a(n)
Ll1-liex23. Miles per Gallon The number of highway miles
pet gallon of the 10 worst vehicles is shown. '
,
O
12
15
13
14
15
16
17
16
17
Source: Pittsburgh Post Gazette,
Find each of these.
a. Mean
I5
b. Median t 5
c.
d.
e.
f
g.
Mode
.~
.5
JS
I U1J
Midrange }5
Range Co
Variance 3 ls:,I
Standarddeviation
.
I,
'. q
a. A quartile
b. A percentile
Find each of these.
a.
Mean
b. Modal class
C»Sf/I
to-~
D
':.
~ "'tt
18.'
25. Inches of Rain Shown here is a frequency distribution
for the number of inches of rain received in 1 year in
25 selected cities in the United States.
Number of inches
Frequency
2
3
8
6
3
3
Find each of these.
.;\..5
a. Mean
I ~S'Y.RS
b. Modal class
..:.
F.
m;d eo',Ot
)C~
01.0
13
5.5-20.5
20.5-35.5
35.5-50.5
50.5-65.5
65.5-80.5
80.5-95.5
Bq
.;I.g>
3 ¥ Lf
"3~~
7..Cf
::t6Lf
1-13
5fl
13
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5 ( . _Lf
3';. S- '50-5
31. Test Scores A student scored 76 on a general science
test where the class mean and standard deviation were
82 and 8, respectively; he also scored 53 on a
psychology test where the class mean and standard
deviation were 58 and 3, respectively. In which class
was his relative position higher?
32. Which scorehas the highestrelativeposition?
a. X = 12
X = 10
s=4
b. X = 170
X = 120
s = 32
c. X = 180
X = 60
s=8
)
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b)
3
O.r:;
Q.,
,sh;S
/70- ,O
/
h-t
. (0
J /89.=.C90
€
IS
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o
33.
Sizes of
of 8Malls
number
feet (in
millions)
of theThe
largest
mallsofinsquare
southwestern
Pennsylvania is shown.
1
0.9
1.3
0.8
1.4
0.77
0.7
1.2
Source: International
Council of Shopping Centers.
a. Find the percentile for each value.
b. What value corresponds to the 40th percentile?
c. Construct a boxplot and comment on the nature of
the distribution.
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