He graph displays Coffee Sales. An x y graph is shown titled Coffee Sales. The x axis is labeled Cups of Coffee Sold and ranges from zero to ten. The y axis is labeled Dollars and ranges from zero to ten. Six points are plotted on the graph. (one, one and one half), (two, three), (three, four and one half), (four, six), (five, seven and one half), and (six, nine).
Based on the graph, what is the cost of one cup of coffee?