Visualization of Multivariate Data DATA-SCIENCE-OPTIMIZE Practice Questions (Page 3)

Questions 11–15

1. 11application · medium

   An energy analyst has data on 100 power plants with 6 numeric attributes (capacity, efficiency, emissions, cost, age, output). The analyst wants to identify which plants have an unusual combination of high efficiency and low emissions compared to the rest. Which visualization is most effective for spotting these outliers across all 6 attributes?

   • AA scatterplot matrix of all 6 attributes.
   • BA bar chart of the average of all 6 attributes per plant.
   • CA heatmap of the 6 attributes for each plant.
   • DA parallel coordinates plot with the 6 attributes as axes.
   Reveal Solution Discussion Select an answer first
2. 12foundation · easy

   What is 'brushing' in the context of interactive multivariate visualization?

   • ARemoving outliers from the dataset permanently.
   • BSelecting a subset of data points by drawing a region (e.g., a rectangle or lasso) around them in one view.
   • CChanging the color palette of the visualization.
   • DAutomatically sorting the data by a chosen variable.
   Reveal Solution Discussion Select an answer first
4. 13foundation · easy

   What is the primary challenge when visualizing data that has more than two variables?

   • AStatistical software cannot compute summary statistics for more than two variables.
   • BMultivariate data cannot be displayed on a two-dimensional screen.
   • CThe human visual system cannot perceive more than two spatial dimensions at once.
   • DMultivariate data always contains missing values that prevent any visualization.
   Reveal Solution Discussion Select an answer first
5. 14application · easy

   A marketing analyst has a dataset with 3 variables: advertising spend, number of impressions, and sales revenue. The analyst wants to visualize all three variables simultaneously to see how they interact. Which of the following is a valid approach?

   • AA line chart with time on the x-axis and spend on the y-axis.
   • BA 3D scatter plot with spend, impressions, and revenue on the three axes.
   • CA bar chart with spend on the x-axis and revenue on the y-axis.
   • DA pie chart of spend, impressions, and revenue.
   Reveal Solution Discussion Select an answer first
6. 15foundation · easy

   What is the main purpose of a correlation matrix?

   • ATo display the raw data values for all observations.
   • BTo summarize the strength and direction of linear relationships between pairs of variables.
   • CTo show the distribution of each variable individually.
   • DTo identify outliers in the dataset.
   Reveal Solution Discussion Select an answer first