Which tool is used to test for a possible cause and effect relationship between two variables?

Which tool is used to test for a possible cause and effect relationship between two variables?

• A. Scatter diagram
• B. Histogram
• C. Control chart
• D. Pareto chart

Answer: (A)

The main idea is to see whether changes in one variable tend to accompany changes in another. A scatter diagram does this by plotting paired data points, with one variable on the horizontal axis and the other on the vertical axis. If the points cluster along a rising or falling pattern, you get a visual cue that a relationship exists—positive if they both increase together, negative if one goes up while the other goes down. This kind of pattern helps you form hypotheses about possible factors causing the outcome and guides further testing to explore causality. If there’s no clear pattern, the variables may be unrelated. This differs from a histogram (which shows how a single variable is distributed), a control chart (which tracks process performance over time to detect variation), and a Pareto chart (which ranks problems or causes by frequency or impact). The scatter diagram is specifically about the relationship between two variables, making it the best fit for testing a possible cause-and-effect link.

The main idea is to see whether changes in one variable tend to accompany changes in another. A scatter diagram does this by plotting paired data points, with one variable on the horizontal axis and the other on the vertical axis. If the points cluster along a rising or falling pattern, you get a visual cue that a relationship exists—positive if they both increase together, negative if one goes up while the other goes down. This kind of pattern helps you form hypotheses about possible factors causing the outcome and guides further testing to explore causality. If there’s no clear pattern, the variables may be unrelated.

This differs from a histogram (which shows how a single variable is distributed), a control chart (which tracks process performance over time to detect variation), and a Pareto chart (which ranks problems or causes by frequency or impact). The scatter diagram is specifically about the relationship between two variables, making it the best fit for testing a possible cause-and-effect link.