Business Analytics exam questions
and answers graded A+
Histogram - ANS✅✅a graph for a quantitative variable; we usually slice up all the possible values
into bins and then count the number of cases that fall in each bin
Relative frequency histograms - ANS✅✅percentages of each bin in the histogram
Stem-and-leaf displays - ANS✅✅are like histograms, but they also give the individual values
Quantitative Data Condition - ANS✅✅Before making a histogram or stem-and-leaf display; the
data must be values of a quantitative variable whose units are known
When describing a distribution, attention should be paid to - ANS✅✅its shape, center, spread
Shape - ANS✅✅a distribution in terms of its modes, its symmetry, and whether it has any gaps or
outlying values
Modes - ANS✅✅Peaks or humps seen in a histogram
Unimodal - ANS✅✅A distribution whose histogram has one main peak
Bimodal - ANS✅✅Two main peaks
Multimodal - ANS✅✅three or more peaks
Uniform - ANS✅✅A distribution whose histogram doesn't appear to have any mode and in which
all the bars are approximately the same height
Symmetric - ANS✅✅the halves on either side of the center look, at least approximately, like mirror
images
,Tails - ANS✅✅The thinner ends of a distribution
Skewed - ANS✅✅If one tail stretches out farther than the other: skewed to side of where tail is
Judgment call - ANS✅✅Characterizing the shape of a distribution
The mean is a natural summary for - ANS✅✅unimodal, symmetric distributions
Mean - ANS✅✅sum of y values (or x values)/ number of variables
If a distribution is skewed, contains gaps, or contains outliers, then it is better to use - ANS✅✅the
median
The median is - ANS✅✅resistant
Range - ANS✅✅max-min; not resistant to unusual observations
quartiles - ANS✅✅values that frame the middle 50% of the data. One quarter of the data lies
below the lower quartile, Q1, and one quarter lies above the upper quartile, Q3
The interquartile range (IQR) - ANS✅✅defined to be the difference between the two quartile
values; Q3-Q1
Standard deviation - ANS✅✅takes into account how far each value is from the mean; appropriate
for symmetric distributions; square root of the variance
Variance - ANS✅✅(s^2) average of the squared deviations; sum of (y value minus the mean)^2 / n-
1
If the shape is skewed - ANS✅✅the median and IQR should be reported
If the shape is unimodal and symmetric - ANS✅✅the mean and standard deviation and possibly
the median and IQR should be reported
, Always pair the median with - ANS✅✅IQR
Always pair the mean with - ANS✅✅standard deviation
Z-score - ANS✅✅the standardized value tells how many standard deviations each value is above or
below the overall mean; x minus the mean/ standard deviation
The five-number summary of a distribution - ANS✅✅reports its median, quartiles, and extremes
(maximum and minimum)
Boxplot - ANS✅✅highlights several features of the distribution of the variable, including the
quartiles, the median, and any outlying values
Time series plot - ANS✅✅A display of values against time
Smooth trace - ANS✅✅To better understanding the trend of times series data
Stationary - ANS✅✅when a time series is without a strong trend or change in variability
Scatterplot - ANS✅✅plots one quantitative variable against another, is an effective display to look
for trends, patterns, and relationships between two quantitative variables
Negative pattern - ANS✅✅A pattern that runs from the upper left to the lower right
Positive pattern - ANS✅✅A pattern running from the lower left to the upper right
Linear - ANS✅✅If there is a straight-line relationship, it will appear as a cloud or swarm of points
stretched out in a generally consistent, straight form
Form - ANS✅✅straight, curved, exotic
Strength - ANS✅✅how much scatter or cluster
and answers graded A+
Histogram - ANS✅✅a graph for a quantitative variable; we usually slice up all the possible values
into bins and then count the number of cases that fall in each bin
Relative frequency histograms - ANS✅✅percentages of each bin in the histogram
Stem-and-leaf displays - ANS✅✅are like histograms, but they also give the individual values
Quantitative Data Condition - ANS✅✅Before making a histogram or stem-and-leaf display; the
data must be values of a quantitative variable whose units are known
When describing a distribution, attention should be paid to - ANS✅✅its shape, center, spread
Shape - ANS✅✅a distribution in terms of its modes, its symmetry, and whether it has any gaps or
outlying values
Modes - ANS✅✅Peaks or humps seen in a histogram
Unimodal - ANS✅✅A distribution whose histogram has one main peak
Bimodal - ANS✅✅Two main peaks
Multimodal - ANS✅✅three or more peaks
Uniform - ANS✅✅A distribution whose histogram doesn't appear to have any mode and in which
all the bars are approximately the same height
Symmetric - ANS✅✅the halves on either side of the center look, at least approximately, like mirror
images
,Tails - ANS✅✅The thinner ends of a distribution
Skewed - ANS✅✅If one tail stretches out farther than the other: skewed to side of where tail is
Judgment call - ANS✅✅Characterizing the shape of a distribution
The mean is a natural summary for - ANS✅✅unimodal, symmetric distributions
Mean - ANS✅✅sum of y values (or x values)/ number of variables
If a distribution is skewed, contains gaps, or contains outliers, then it is better to use - ANS✅✅the
median
The median is - ANS✅✅resistant
Range - ANS✅✅max-min; not resistant to unusual observations
quartiles - ANS✅✅values that frame the middle 50% of the data. One quarter of the data lies
below the lower quartile, Q1, and one quarter lies above the upper quartile, Q3
The interquartile range (IQR) - ANS✅✅defined to be the difference between the two quartile
values; Q3-Q1
Standard deviation - ANS✅✅takes into account how far each value is from the mean; appropriate
for symmetric distributions; square root of the variance
Variance - ANS✅✅(s^2) average of the squared deviations; sum of (y value minus the mean)^2 / n-
1
If the shape is skewed - ANS✅✅the median and IQR should be reported
If the shape is unimodal and symmetric - ANS✅✅the mean and standard deviation and possibly
the median and IQR should be reported
, Always pair the median with - ANS✅✅IQR
Always pair the mean with - ANS✅✅standard deviation
Z-score - ANS✅✅the standardized value tells how many standard deviations each value is above or
below the overall mean; x minus the mean/ standard deviation
The five-number summary of a distribution - ANS✅✅reports its median, quartiles, and extremes
(maximum and minimum)
Boxplot - ANS✅✅highlights several features of the distribution of the variable, including the
quartiles, the median, and any outlying values
Time series plot - ANS✅✅A display of values against time
Smooth trace - ANS✅✅To better understanding the trend of times series data
Stationary - ANS✅✅when a time series is without a strong trend or change in variability
Scatterplot - ANS✅✅plots one quantitative variable against another, is an effective display to look
for trends, patterns, and relationships between two quantitative variables
Negative pattern - ANS✅✅A pattern that runs from the upper left to the lower right
Positive pattern - ANS✅✅A pattern running from the lower left to the upper right
Linear - ANS✅✅If there is a straight-line relationship, it will appear as a cloud or swarm of points
stretched out in a generally consistent, straight form
Form - ANS✅✅straight, curved, exotic
Strength - ANS✅✅how much scatter or cluster
