What type of line graph is used to assess the stability of a process?

A control chart is a specific type of line graph that serves the purpose of assessing the stability and performance of a process over time. It includes data points plotted against a time scale, as well as control limits that represent the expected variation in the process. These control limits help determine whether a process is operating within expected parameters or if there are variations that may signal an issue.

By analyzing the pattern of data points on a control chart, practitioners can identify trends, shifts, or other signals indicating that a process is becoming unstable or is operating as intended. This makes control charts an essential tool in quality control and continuous improvement efforts within various industries. The other options, such as histograms, flow charts, and scatter plots, serve different purposes related to data analysis and visualization, but they do not specifically focus on monitoring process stability over time in the way that control charts do.