Do math into value coming from 2 separated tables

Hello all,
I still don't understand how I can calculate a number, issues from data not directly linked between them.

For example, on the following screenshots, you can see on the left "Calls by PM", it is from a certain table, that is what we have done. On the right, you have "Experts required" coming from another table, that is what our clients ordered.
CleanShot 2024-07-30 at 12.26.28

I would like to calculate the % of success. I have these two numbers but I don't know how to do...
CleanShot 2024-07-30 at 12.31.08 Do math into value coming from 2 separated tables