A linear relationship (or linear association) is a statistical term used to describe the directly proportional relationship between a variable and a constant.

Capture relationships between data sets by graphing linear equations in Microsoft Excel 2007. Linear equations allow you to predict values within your data set and view the overall trend. Use ...

A linear equation is drawn as a straight line on a set of axes. To draw the graph we need coordinates. We generate these coordinates by substituting values into the linear equation.

Worked examples When asked to solve a quadratic equation, we are really finding the roots – where the parabola cuts the x-axis, therefore when we have the graph drawn, it is very easy to do this.

The top part of that image is the equation itself. The bottom part is a graph of the equation, which, as you can see, is exactly the same. To be fair, this equation cheats a little bit.