how to add both sum() and avg()?

Question

I want to have both sum and avg metrics in the same table but I get an error...

My goal is to get a table with avg and the total sum, like:

> agent    avg()   sum()
> 
> agent1   3.34    35000
> 
> agent2   5.91    850

...

But I get this error:

Answer 1

If I do it manually it works:

I added:

Why would it work manually and not when I use the automatic avg() from the dropdown...?!