Why do you divide by 2 get get the area under a linear graph?

This question applies to finding the amount of work done.

Let's say I did an experiment where I pulled a spring. Let 'x' be the distance I pulled the string and f(x) be the force required to pull the ptring.

The result of the experiment is:

x (Meters):1,2,3,4,5,6,7,8,9,10

f(x) (Newtons):2,3,4,5,6,7,8,8,10,11

If I was to graph the data, I would get a linear line. To get the total amount of work done, wouldn't I just have to multiply the final distance

by the final amount of force (required to pull the spring)?

After all W = Force * Distance.

---

If I were to graph the CHANGE in distance (delta X) against the amount of force required, would I still have to divide by 2?