Depending on the quantities, it can be anything that you like!
A graph.
It shows a relationship among certain quantities.
The relations between quantities are stated by multiplicative relationship between the quantities.
an equation that expresses a relationship between two or more quantities
The answer depends on the quantities and the nature of the relationship. It can be a line-of-best-fit (or regression line), or a formula.
The relationship between two quantities that increase or decrease together is called a positive correlation. This means that as one quantity increases, the other quantity also increases, and vice versa.
It is a non-linear or non-existent relationship between the two quantities.
parabola
A proportional relationship between two quantities is one in which the two quantities called the unit rate, the rate of change, or the constant of proportionality.
A ratio shows the relationship between two quantities.Formula
Function
It is a ratio
A formula.