Line graph with 1 row as 100%

[#1]

Hi, I'm busy to build a chart with a cummul.

I will show my case with a simple example.

ID        Cat      Price

-----------------------------

1          A          50

2          B          10

3          C          20

4          D          30

Now my question: I want to make a line graph with Cat D (Category D) as 100%.
So Category A would be higher than 100%...

How can I fix this?
Should I make calculeted dimension, with a where statement where stands: Where Cat = D???

Please some help?

Regards,