Calculate total person cost when multiple people are selected to work on project

I hope this is a very simple problem that I can’t seem to solve.

I have two tables: projects and people. There is a multi-select column that I use to select who is working on a project. When I select multiple people I want to see the total of their combined rates.

I just find the right formula.

Thanks

Dear @Gaz_Lloyd-Owen,

Please would you mind to update the sharing settings of your document?

I have the feeling that this post is what you are after:

Hi @Jean_Pierre_Traets . Thanks for looking at this. I’ve corrected the settings for the doc. I did look at the option you provided but still couldn’t get the right calculation even after add the option 3 formula suggestion. I must be missing something.

Dear @Gaz_Lloyd-Owen,

I added the formula in the doc

Thanks @Jean_Pierre_Traets. So simple.