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CHAPTER 4 SECTION 2: NUMERICAL DESCRIPTIVE TECHNIQUES
MULTIPLE CHOICE
75.
A sample of 20 observations has a standard deviation of 3. The sum of the squared deviations from the
sample mean is:
a.
20.
b.
23.
c.
29.
d.
171.
ANS: D
PTS:
1
REF:
SECTION 4.2
76.
If two data sets have the same range:
a.
the distances from the smallest to largest observations in both sets will be the same.
b.
the smallest and largest observations are the same in both sets.
c.
both sets will have the same standard deviation.
d.
both sets will have the same interquartile range.
ANS: A
PTS:
1
REF:
SECTION 4.2
77.
The Empirical Rule states that the approximate percentage of measurements in a data set (providing that
the data set has a bell shaped distribution) that fall within two standard deviations of their mean is
approximately:
a.
68%.
b.
75%.
c.
95%.
d.
99%.
ANS: C
PTS:
1
REF:
SECTION 4.2
78.
Which of the following summary measures is affected most by extreme values?
a.
The median.
b.
The mean.
c.
The range.
d.
The interquartile range.
ANS: C
PTS:
1
REF:
SECTION 4.2
79.
Chebysheff's Theorem states that the percentage of measurements in a data set that fall within three
standard deviations of their mean is:
a.
75%.
b.
at least 75%.
c.
89%.
d.
at least 89%.
ANS: D
PTS:
1
REF:
SECTION 4.2
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80.
Which of the following is a measure of variability?
a.
The interquartile range
b.
The variance
c.
The coefficient of variation
d.
All of these choices are true.
ANS: D
PTS:
1
REF:
SECTION 4.2
81.
The smaller the spread of scores around the mean:
a.
the smaller the variance of the data set.
b.
the smaller the standard deviation of the data set.
c.
the smaller the coefficient of variation of the data set.
d.
All of these choices are true.
ANS: D
PTS:
1
REF:
SECTION 4.2
82.
Is a standard deviation of 10 a large number indicating great variability, or is it small number indicating
little variability? To answer this question correctly, one should look carefully at the value of the:
a.
mean.
b.
standard deviation.
c.
coefficient of variation.
d.
mean dividing by the standard deviation.
ANS: C
PTS:
1
REF:
SECTION 4.2
83.
Which of the following types of data has no measure of variability?
a.
Interval data
b.
Nominal data
c.
Bimodal data
d.
None of these choices.
ANS: B
PTS:
1
REF:
SECTION 4.2
84.
Which of the following statements is true regarding the data set 8, 8, 8, 8, and 8?
a.
The range equals 0.
b.
The standard deviation equals 0.
c.
The coefficient of variation equals 0.
d.
All of these choices are true.
ANS: D
PTS:
1
REF:
SECTION 4.2
TRUE/FALSE
85.
The value of the standard deviation may be either positive or negative, while the value of the variance
will always be positive.
ANS: F
PTS:
1
REF:
SECTION 4.2
86.
The difference between the largest and smallest observations in an ordered data set is called the range.
ANS: T
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 Spring '10
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