Most graphs involve a horizontal axis and a vertical axis.
All graphs should have a title, labelled axes with the scale and units clearly indicated.
Rates of Change
A rate compares two quantities of a different kind. Because two quantities are being compared, a graph with two axes is a convenient way to illustrate this.
e.g. Speed = kilometre per hour .
The graph below shows the distance travelled by a cyclist on a journey over a period of 10 hours.
Notice that time is usually on the horizontal axis in this type of graph and that the steeper the graph (i.e. the bigger the gradient) the greater the speed (i.e. the quicker the cyclist is travelling.)
A scatter graph is a useful way to compare two quantities to see if there is a relationship between them.
Compare the heights and weights of the following six people and see if there is a connection between their heights and weights.
From the graph, there would appear to be a connection between height and weight.
The heavier the person the taller they are.
Remember this is only for these six people and may not be true for a larger group or for people in general.