Matrix - Show Effect on Percentage with Row Value Removed

[Brotedo]

I have an accuracy measure, given as a percentage, for each customer, and I want to be able to show (in a matrix) what that percentage would be if I remove a particular item from the calculation.

For example, suppose the measure for Customer A is 75% across all items, but if Customer A bought none of Item 1, it would be 78%, and if they bought none of Item 2, it would be 64%. I want this:

Item	Total Accuracy	Accuracy with Item Removed
Item 1	75%	78%
Item 2	75%	64%

[lbendlin]

 if I remove a particular item from the calculation

How do you plan to do that?  A slicer fed by a disconnected table?