determine how much more revenue the $3,500 television produced. There were 150 of the $3,500
televisions sold, for a revenue of $525,000. There were 250 of the $1,000 televisions sold, for a revenue
of $250,000. The difference between the two is $525,000 – $250,000 = $275,000, as seen in (C).
A question may ask you to draw a “line of best fit” on a scatterplot diagram. This is the line that best
represents the data. You can use the edge of your answer sheet as a ruler to help you draw a line that goes
through most of the data.
The Line Graph
A line graph is similar to a scatterplot in that it shows different data points that relate the two variables.
The difference with a line graph, though, is that the points have been connected to create a continuous line.
Here’s How to Read It
Reading a line graph is very similar to reading a scatterplot. Start at the axis that represents the data
given, and draw a straight line up or to the right until you intersect the graph line. Then move left or down
until you hit the other axis. For example, in February, indicated by an F on the horizontal axis, Always
Sunny sunscreen had 2.5 million in sales. Make sure to notice the units on each axis. If February sales
were only $2.50, rather than $2.5 million, then this company wouldn’t be doing very well!
Let’s look at a question about this line graph.