Quiz Over Chapter 2 of the
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, how many students exercised vigorously less than 3 days a week?
- 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 Excerpts 2.4 and 2.5, each vertical bar reveals information about a portion of the
collected data by means of the vertical bar's _______ (width/height).
- A normal distribution is often said to be "___-shaped."
- (T/F) In Excerpt 2.6, the distribution of ages would have resembled more closely
a normal distribution if 24% of the group had been between the ages of 21-25, with only 8%
of the group between the ages of 26-30.
- What kind of skewness is associated with the data shown in Excerpt
- Based on the information displayed in Excerpt 2.7, 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 2.7, if the bars over the scores of 1 and 11 had been
reversed, and if the bars over the scores of 1 and 12 had been reversed,
there would have been ____ (more/less) variability among the study's patients.
- 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 2.16, what percentage of the participants were between 28 and 59
- (T/F) Researchers rarely report both the SD and the variance for
the same data set.
- In Excerpt 2.20, the variance of the third variable (Number of places slept last
week) would be equal to ___.
- (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 ___.
- If N = 100 and SD = 10, you should guess that the range of scores = ___ .
- 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 __.
- Look again at Excerpt 2.20, and concentrate on the 3rd variable (Number of places
slept last week). If one of the research participants had slept in 5 different
places, that participant's z-score would be equal to ___ .
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 2.27, a rule for identifying outliers is articulated.
If that rule is applied to the age data in Excerpt 2.19,
are there any outliers?
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