Quiz (Chapter 2)
Picture Techniques for Summarizing Data
- If you add all the numbers in the "f" column of an ungrouped frequency
distribution, you'll get ___ .
- In Excerpt 2.1, what is the cumulative frequency for TAS scores
up to and including 2?
- How would you interpret this if it were presented in a stem-and-leaf
- What determines the height of each "bar" in a histogram?
- The technical names for the horizontal and vertical axes in a bar
graph or line graph are ____ and ____ , respectively.
- "Frequency polygon" is to "line graph" as "_____" is to "bargraph."
- When raw scores are summarized via a grouped frequency distribution,
is there "loss of information?" What about when raw scores are
summarized via a stem-and-leaf display?
- In Excerpt 2.5, what are the compliance scores summarized on the
bottom row of the stem-and-leaf display?
- A normal distribution is often said to be "___-shaped."
- (T/F) In Excerpt 2.6, the histrogram would have more closely
resembled a normal distribution if there had been 18 individuals with
score of 12.
- What kind of skewness is associated with the data shown in Excerpt
- Based on the information presented in Excerpt 2.9, the "extreme"
scores were _____ (high/low).
- What does a leptokurtic distribution look like? A platykurtic
- What are the numerical values for skewness & kurtosis for a symmetrical
Measures of Central Tendency
- (T/F) In the field of statistics, the term "average" is used to signify
only the mean.
- Which measure of central tendency gives the "middle score" (or "mid-point")?
- What's the median & mean for: 14, 4, 10, 8, 6, 12, 16?
Change 16 to 86 and re-answer.
- Which measure of central tendency assumes the highest score in skewed
- What Greek letter is sometimes used to signify the mean?
- If the mean, median, and mode are 50, 60, and 70, respectively, does
that suggest negative skewness?
Measures of Variability
- In Excerpt 2.6, if the bars over the scores of 3 and 11 had been
reversed and if the bars over the scores of 14 and 20 had been reversed,
there would have been ____ (more/less) variability in the data from
- How many quartiles are there? How are they labeled? Which
one is the highest?
- What is the name for the numerical distance between the 75th and
- For these data, what is the semi interquartile range equal to?
9, 1, 6, 5, 4, 7, 2, 5
- (T/F) The semi interquartile range is always equal to one-half the
distance between Q1 & Q3.
- In Excerpt 2.21, the middle 50 percent of the 32 pain scores
at baseline were between ___ and ___ .
- (T/F) Researchers rarely report both the SD and the variance for
the same data set.
- In Excerpt 2.26, the variance of the Digit Span scores was equal
to about ___.
- (T/F) If all of the scores are negative, the SD itself will turn
out to be a negative value.
- One symbol for the variance is s2; another symbol for
the variance is ___.
- (T/F) Based on the information in Excerpt 2.24, we should guess that
the oldest young adult was about 9 years older than the youngest young
- If a researcher summarizes his/her data by saying 38 ±
12, what does the 12 indicate?
- If a group of scores has a mean equal to 10 and a SD equal to 20,
the coefficient of variation will be equal to ___.
- A standard score simply indicates the number of ____ between a raw
score and ____.
- A z-score of +1.5 is equal to a T-score of __. A T-score of
48 is equal to a z-score of __.
- Based on the information in Excerpt 1.9 (in Chapter 1), one of the
students who self-reported having a "B" GPA would have had a Locus
of Control score of ___ if his/her T-score
equal to 60.
A Few Cautions
- (T/F) Researchers sometimes use the term "skewed" to mean something
other than "positively skewed" or "negatively skewed."
- (T/F) If a researcher uses the term "average" without specifying
whether it's the mean, median, or mode, you'll most likely be correct
if you guess that it's the median.
- A score in a data set that lies far away from the rest of the scores
is called a(n)_____.
- In Excerpt 2.35, a rule for identifying outliers is articulated.
If that rule had been applied to the 6-month data in Excerpt 2.21,
would there have been any outliers?
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