Adding formula to one cell

It won’t be simple, but it’s possible. Here’s my first ideas:

1. You need to sum the desired salaries by linking all records you want to add to a single record (this single record, let’s call it ‘SUM’ can be either in this table or a separate table). By doing this, you can aggregate the sum of all salaries, etc. (Airtable recently added the ability to sum data linked in the same table, so bear with me as I’m used to doing this in a separate table).
2. You will then need to create a Rollup field in the same table with your SUM record. This Rollup field should SUM() the linked records.
3. Now to filter this down to get what you want. I’m guessing your existing far-right column is a formula of some sort that calculates the Salaries for each type of employee/service area. In this formula, or a new field, you need to basically create an IF() statement that says IF the [insert column title of left-most column with Payroll Taxes, etc.] = ‘Payroll Taxes’, then {SUM [your linked salary sum]}*.2, otherwise [insert your existing formula which calculates the salaries].
   Note there are many ways to do this last step. Basically, you want to tell this IF formula to multiple by the 0.2 (or 20%) only if the record = ‘Payroll Taxes’ and for all other records, just show the Salary result - or something to that effect.

Tried to keep this brief to just give an idea of how this can be accomplished - but the benefit of Airtable is that there’s probably 3+ other ways to do it. Just my first impressions. If you have more detail as to the column titles I could polish this up / try and have it make more sense :grinning_face_with_sweat: