What type of graph is primarily used to show continuous events?

The correct answer is that line graphs are primarily used to show continuous events. Line graphs excel at displaying data points in time-series formats where the independent variable (often time) is continuous. They effectively illustrate trends over intervals, allowing viewers to observe how one variable changes in relation to another over time.

For example, a line graph could depict the progression of a patient's blood pressure readings over several days, enabling the healthcare professional to quickly identify trends such as increasing or decreasing values. This visualization helps in monitoring changes that occur continuously rather than at discrete intervals.

When comparing to other types of graphs, pie charts are typically used to represent parts of a whole rather than showing trends over time. Histograms visualize the frequency distribution of discrete data in intervals but do not effectively show continuous changes. Bar graphs illustrate categorical data and differences between groups more effectively than trends over time. Line graphs, therefore, are the most appropriate choice for representing continuous events and demonstrating how values evolve.