What quality control chart compares two or more variables over time to determine how closely the variables may be related to one another?

A run chart displays a single variable plotted over time to reveal trends or shifts in a process, not the relationship between multiple variables.

A scatter diagram plots one variable on the x-axis and another on the y-axis to display paired data points, allowing the team to visually assess whether a correlation exists between the two variables and how strong that relationship is. It is one of the seven basic quality tools used in quality control analysis.

A control chart monitors whether a single process measurement is within defined statistical control limits over time, not the correlation between two or more variables.

A Pareto diagram ranks categories of defects or problems by frequency to prioritize corrective efforts, not to compare variable relationships.