What is the function of a scatter diagram in data analysis?

The function of a scatter diagram in data analysis is to visualize relationships between two variables. This type of diagram presents data points on a Cartesian coordinate system, where one variable is plotted on the x-axis and the other on the y-axis. By examining the pattern of points, one can determine if there is a correlation or association between the two variables. If the points tend to cluster in a linear pattern, it suggests a strong relationship; if they are spread out randomly, it suggests little or no relationship.

While other options describe important analytical tools or methods, they do not accurately represent the primary purpose of a scatter diagram. For example, tracking progress over time is typically done with line graphs, showing changes across different time intervals. Similarly, showing the frequency of errors is more suited to histograms or bar charts, which indicate how frequently certain values occur within a dataset. Lastly, analyzing leadership effectiveness usually involves qualitative assessments or performance metrics rather than the quantitative relationship depicted in a scatter diagram. Thus, the scatter diagram specifically excels in highlighting correlations between two variables, making option B the correct choice.