Which graphical measurement tool illustrates a trend over time using a line graph?

The correct choice illustrates a trend over time using a line graph, which is the defining characteristic of a run chart. A run chart displays data points in a sequential order, allowing viewers to observe how a particular variable behaves over time. It helps identify trends, shifts, and patterns in the data, making it an effective tool for monitoring performance and changes in a process.

The run chart’s simplicity allows stakeholders to easily understand trends and variations without needing extensive statistical analysis. This makes it especially useful in environments where continuous measurement is critical, such as in quality control or project management.

In contrast, other graphical tools mentioned serve different purposes. A Pareto chart is used to highlight the most significant factors in a dataset, often represented by a bar graph, while a scatter diagram examines relationships between two variables rather than trends over time. A fishbone chart, also known as a cause-and-effect diagram, focuses on identifying potential causes of a problem rather than tracking changes over a duration. Each of these tools has its specific application but does not serve the function of illustrating trends over time like the run chart does.