Now try to adjust the points, click once on the point you have already plotted and then use your arrow keys to move the point to the correct (x,y) coordinates. The points can be shifted up, down, left, and right by using the arrow keys. Fill in the graph illustrating your total cost under this plan.

Plot the points

for the costs at

30,

60,

and

120

minutes, then

plot the line

for the total costs. (Enlarge the graph to medium size and use the point tool and line tool buttons displayed below to draw the graph.)

010203040506070809010011012013005101520253035404550MinutesDollars

interactive graphClick to enlarge graph