Sum from related table

[cdfisher89]

I am trying to sum values that are on other tables onto a master table, but I can't seem to get it to work.  It is essentially a Sumif function, but I can't seem to get Calculate and or SUMX to work.  It always wants to return the fee for the entire related table (Revenue or Time).

Please see the below image.  I am trying to sum Fees and Hours onto the Assignments table for the individual assignments.  The Revenue and Time tables are linked to Assignments.