MBA 613 - Midterm Questions with Verified Solutions Graded A+
What is descriptive statistics? - Answers It summarizes the center, spread, and shape of data,
helping identify unusual values or patterns.
How does the mean compare to the median in right skewed data? - Answers Mean > Median
(long right tail)
How does the mean compare to the median in left skewed data? - Answers Mean < Median
(long left tail)
What is the interquartile range (IQR)? - Answers It is represents the spread of the middle 50% of
data.
How do you calculate the IQR? - Answers Q3 - Q1 or 75 Quartile - 25 Quartile
How do you identify outliers using IQR? - Answers Data points below Q1 - 1.5 × IQR or above Q3
+ 1.5 × IQR are potential outliers.
What is the purpose of a boxplot? - Answers Provides a visual summary of data distribution,
median, IQR, and outliers.
What do histograms show? - Answers Displays the distribution of data, indicating normality,
skewness, or bimodality.
Why are histograms useful? - Answers They reveal gaps, spikes, or distribution patterns that
may indicate data quality issues.
What is the importance of exploratory data analysis? - Answers It helps catch errors, outliers,
and guides the selection of modeling techniques.
What is the difference between normal and skewed distribution? - Answers Normal:
Symmetrical, bell-shaped curve, Skewed: Asymmetrical, with a tail on one side.
What is the shape of a skewed distribution? - Answers Asymmetrical, with a tail on one side.
What is the shape of a normal distribution? - Answers Symmetrical, bell-shaped curve
What is a z-score? - Answers Measures how many standard deviations a data point is from the
mean.
What does a positive z-score indicate? - Answers The data point is above the mean.
What does a negative z-score indicate? - Answers The data point is below the mean.
What is the empirical rule? - Answers About 68% of data falls within 1 StdDev, 95% within 2
StdDevs, and 99.7% within 3 StdDevs of the mean.
, What is variance? - Answers It measures the average squared deviation from the mean.
What is the relationship between variance and StdDev? - Answers It is the square root of
variance.
What is covariance? - Answers It measures how two variables change together.
What is correlation? - Answers It measures the strength and direction of the relationship
between two variables.
How is correlation measured? - Answers With the correlation coefficient, ranging from -1 to 1.
What does a correlation of 0 mean? - Answers No linear relationship between variables.
What is the primary purpose of descriptive statistics? - Answers To summarize the center,
spread, and shape of data and identify unusual values or patterns that could impact analysis.
What does standard deviation measure? - Answers It measures how far each data point is from
the mean, on average.
What does a low standard deviation indicate? - Answers Values are tightly clustered around the
mean.
What does a high standard deviation indicate? - Answers Values are more widely spread out
from the mean.
What does it mean if the mean is greater than the median? - Answers The data is right-skewed,
with a long tail on the right.
What does it mean if the mean is less than the median? - Answers The data is left-skewed, with
a long tail on the left.
What is the purpose of calculating the IQR? - Answers To identify the range of the middle 50% of
data and flag potential outliers.
How is a potential outlier determined using the IQR? - Answers If a data point is below Q1 - 1.5 ×
IQR or above Q3 + 1.5 × IQR, it is considered a potential outlier.
What visual representation provides a compact summary of IQR and outliers? - Answers A
boxplot.
What does the "box" in a boxplot represent? - Answers It spans from Q1 to Q3 (the IQR), with a
line at the median.
What do the "whiskers" in a boxplot represent? - Answers They extend to the smallest and
largest non-outlier values.
What do dots or stars beyond the whiskers in a boxplot represent? - Answers Potential outliers.
What is descriptive statistics? - Answers It summarizes the center, spread, and shape of data,
helping identify unusual values or patterns.
How does the mean compare to the median in right skewed data? - Answers Mean > Median
(long right tail)
How does the mean compare to the median in left skewed data? - Answers Mean < Median
(long left tail)
What is the interquartile range (IQR)? - Answers It is represents the spread of the middle 50% of
data.
How do you calculate the IQR? - Answers Q3 - Q1 or 75 Quartile - 25 Quartile
How do you identify outliers using IQR? - Answers Data points below Q1 - 1.5 × IQR or above Q3
+ 1.5 × IQR are potential outliers.
What is the purpose of a boxplot? - Answers Provides a visual summary of data distribution,
median, IQR, and outliers.
What do histograms show? - Answers Displays the distribution of data, indicating normality,
skewness, or bimodality.
Why are histograms useful? - Answers They reveal gaps, spikes, or distribution patterns that
may indicate data quality issues.
What is the importance of exploratory data analysis? - Answers It helps catch errors, outliers,
and guides the selection of modeling techniques.
What is the difference between normal and skewed distribution? - Answers Normal:
Symmetrical, bell-shaped curve, Skewed: Asymmetrical, with a tail on one side.
What is the shape of a skewed distribution? - Answers Asymmetrical, with a tail on one side.
What is the shape of a normal distribution? - Answers Symmetrical, bell-shaped curve
What is a z-score? - Answers Measures how many standard deviations a data point is from the
mean.
What does a positive z-score indicate? - Answers The data point is above the mean.
What does a negative z-score indicate? - Answers The data point is below the mean.
What is the empirical rule? - Answers About 68% of data falls within 1 StdDev, 95% within 2
StdDevs, and 99.7% within 3 StdDevs of the mean.
, What is variance? - Answers It measures the average squared deviation from the mean.
What is the relationship between variance and StdDev? - Answers It is the square root of
variance.
What is covariance? - Answers It measures how two variables change together.
What is correlation? - Answers It measures the strength and direction of the relationship
between two variables.
How is correlation measured? - Answers With the correlation coefficient, ranging from -1 to 1.
What does a correlation of 0 mean? - Answers No linear relationship between variables.
What is the primary purpose of descriptive statistics? - Answers To summarize the center,
spread, and shape of data and identify unusual values or patterns that could impact analysis.
What does standard deviation measure? - Answers It measures how far each data point is from
the mean, on average.
What does a low standard deviation indicate? - Answers Values are tightly clustered around the
mean.
What does a high standard deviation indicate? - Answers Values are more widely spread out
from the mean.
What does it mean if the mean is greater than the median? - Answers The data is right-skewed,
with a long tail on the right.
What does it mean if the mean is less than the median? - Answers The data is left-skewed, with
a long tail on the left.
What is the purpose of calculating the IQR? - Answers To identify the range of the middle 50% of
data and flag potential outliers.
How is a potential outlier determined using the IQR? - Answers If a data point is below Q1 - 1.5 ×
IQR or above Q3 + 1.5 × IQR, it is considered a potential outlier.
What visual representation provides a compact summary of IQR and outliers? - Answers A
boxplot.
What does the "box" in a boxplot represent? - Answers It spans from Q1 to Q3 (the IQR), with a
line at the median.
What do the "whiskers" in a boxplot represent? - Answers They extend to the smallest and
largest non-outlier values.
What do dots or stars beyond the whiskers in a boxplot represent? - Answers Potential outliers.
