Rate of Change

Example:

Use the table to find the rate of change. Then graph it.

$\begin{array}{|cc|}\hline \text{Time}\text{Driving}(\text{h})x& \text{Distance}\text{Travelled}(\text{mi})y\\ 2& 80\\ 4& 160\\ 6& 240\\ \hline\end{array}$

A rate of change is a rate that describes how one quantity changes in relation to another quantity.

$\begin{array}{l}\text{rate}\text{of}\text{change}=\frac{\text{change}\text{in}y}{\text{change}\text{in}x}\\ =\frac{\text{change}\text{in}\text{distance}}{\text{change}\text{in}\text{time}}\\ =\frac{160-80}{4-2}\\ =\frac{80}{2}\\ =\frac{40}{1}\end{array}$

The rate of change is $\frac{40}{1}$ or $40$ . This means a vehicle is traveling at a rate of $40$ miles per hour.