Possible Duplicate:

Excel axis problem

I jumped from an older version of Excel to the new ribbon interface and am stumped trying to make a simple graph.

I have a set of pair values that go something like this:

```
X Y
1 .5
2 .4
3 .35
4 .33
5 .3
10 .2
15 .15
20 .1
```

When I plot a line graph I get the x-axis as if the X's are text and each one is a category. I would like to get the graph where the 10, 15 and 20 values are put in their proportional place, with gaps between them wider than between the first elements. I'm sure Excel must be able to do this but I can't find how in the new interface.