Measure that sums a calculation for each type

Hi everyone,

I am hoping you can help. As shown in the attached .pbix, I am trying to create a measure that does a calculation for each type of unit.

https://www.dropbox.com/transfer/AAAAAI7QwxfiEXZVRyFwMUAlDwzO_TqBV0YNUKIAgJTeNjcKO2HtDKE

Here's the context:

I have three types of tasks (A,B, and C) that are supposed to take a certain amount of time (target). My data show their actual time compared to their target.

I am supposed to use geometric means (rather than arithmetic means) to show average performance, which I have done through a few measures.

Here is where I need help: To show opportunity, I want to do a summation of the difference between geometric mean acutal and geometric mean target, for each type of task. In the .pbix, I have done this on a row level, but I am not able to aggregate it. My total opportunity shows 0.88 when it should equal 4.99 (0.41+0.25+4.33).

Can anyone help? I'd really apprecaite it!