What term describes a mathematical relationship between two variables?

The term that describes a mathematical relationship between two variables is correlation. Correlation specifically quantifies the degree to which two variables move in relation to each other. This relationship is often expressed in terms of a correlation coefficient, which can range from -1 to +1. A value of 1 indicates a perfect positive correlation, meaning as one variable increases, the other also increases. A value of -1 indicates a perfect negative correlation, meaning as one variable increases, the other decreases. A value of 0 implies no correlation.

While other options like regression, association, and dependence also relate to relationships between variables, they have distinct meanings. Regression refers to a statistical method that models the relationship between a dependent variable and one or more independent variables, often used for prediction. Association can describe a broader relationship but does not necessarily imply a mathematical or quantifiable link. Dependence refers to a condition where the value of one variable is influenced by another, but it is more qualitative rather than a strict mathematical term. Thus, correlation is the most precise term for a mathematical relationship between two variables.