Trying to calculate % expected based on weekly values in PivotTable/OLAP Cube

[nemisis]

Hi, its been a while since I've been here but its good to be back

I have data arranged as below in an OLAP Cube Pivot Table but ideally I would like to add a field that calculates the expected % achieved by a particular day.

Eg for Workday 3 it would be Wk19 24.2%/5 * 3 =14.5%
for Workday 9 it would be Wk19 24.2% + Wk 20 26.0%/5*4 =45%

	Wk19	Wk20	Wk21	Wk22
Test Product 1	24.2%​	26.0%​	24.6%​	25.2%​

Ideally I want to add this as a field but have been struggling, can anyone help?

Thanks all!