ASQ Certified Quality Technician (CQT) Practice Exam 2026 - Free CQT Practice Questions and Study Guide

Both variables showing a pattern together is what correlation describes, but that pattern doesn’t prove that one variable causes the other. Causation means that changing one variable brings about a change in the other, and establishing causation usually requires considering the timing, mechanism, and ruling out other possible explanations. A common way to illustrate this is that two things can move together for a reason other than one causing the other, such as a third factor driving both.

That’s why this statement is the best answer: it correctly defines what correlation means (they vary together) and distinguishes it from causation (one causes the other) while explicitly noting that correlation alone does not establish a causal relationship. The other options misstate the relationship: correlation does not prove causation, causation and correlation are not the same, and correlation is not limited to linear relationships (you can have associations that are not perfectly linear).