Graphing

In this video, let's use a set of data in order to create a line graph. A line graph visually displays the data and is a tremendously useful tool for making predictions without having to do calculations.

To start, look at the labels and intervals of the graph along the x-axis.

The label is seconds and the graph is ranging from zero to 40 counting by ones.

Along the y-axis, the label is centimeters and the graph is ranging from zero to 620 counting by twenties.

The first step in building the graph is to select two data points from the table to plot on the graph.

There's not enough room on the graph to plot these points, so I'm going to choose to plot 15 seconds, 380 centimeters, and five seconds, 126.67 centimeters.

When plotting points, it's so important to be as precise as possible.

So I'm going to take a closer look here as I plot the point five, 126.67.

Because the intervals along the y-axis are increasing by 20, this is going to require a little bit of estimation.

I know this line here represents 140, and this line represents 120, so I think 126.67 should be right here.

And now for the point 15, 380.

Next, beginning at the origin, draw a line that passes through both of these points. It's extremely important to draw a straight line. So use a meter stick for this step.

The points should line up. If for some reason they don't, that's an indicator that you made a mistake plotting the points or with the computation when you created the ratio table.

And that completes my graph. And what's so cool about a graph is that now I can use it to make tons of predictions without having to do any calculations.

For instance, how far would the vehicle travel in 23 seconds?

580 centimeters.