How Graphs can play a role in the daily practice life in solving different kind of problems.
Financial situations, eg. for a stock broker or accountant?
Also there is this show I love, "numb3rs", that is on friday night on CBS. He uses math to solve crime and most of it is decent math that can be used. Apparently they've "butchered Game Theory" but its up to you....
Watch it and find out ^_^
They can be used to draw a relationship between to events. For example, the x scale is the time and the y scale is the amount of money. Thus, by expression the curves as a formula you have an equation that says the amount of money after some time. Then you can use calculus to find where it will be optimal in amount.
A water company, for example, would use graphs to analyze how much water has been used/wasted in a particular day and possibly use that to decide how much water to pump? (I have no idea how the water company works sorry)
A business would use graphs such as one to analyze their business growth. For example, they could plot a net profit graph with time along the x axis. On this graph they could plot their growth in money and predict such things as how long it could take them to break even.
The police could use graphs to analyze growth in crime in particular areas which would give them an idea where to concentrate police patrols in future.
Need any more?