alexjoh89 wrote:
I have a question. If the formula is:
Total = Group1 + Group2 + Group3 - (sum of 2-group overlaps) - 2*(all three) + Neither
why is it then + 4 instead of -2*4?
I got this wrong the first time too. I would advise drawing the venn diagram to see it. The problem is when we subtract the overlap between the 3 groups, we already subtracted the center piece thrice. So we need to add a center piece to get what we want. Your reasoning would be correct if the overlapping piece doesn't cover the center
...
.jpg)
