What does it mean for there to be a linear relationship between variables?

Straight line on a graph is linear it shows variables change at the same time the graph line changes.

Step-by-step explanation:

A linear relationship (or linear association) is a statistical term used to describe a straight-line relationship between a variable and a constant. Linear relationships can be expressed either in a graphical format or as a mathematical equation of the form y = mx + b.

Linear relationships can be expressed either in a graphical format where the variable and the constant are connected via a straight line or in a mathematical format where the independent variable is multiplied by the slope coefficient, added by a constant, which determines the dependent variable