I have 1 known Ashkenazi great grandparent of 8. One eight is 12.5%.It is more likely that you inherited more than your proportionate
share of your ggp's dna.
We each receive half our dna >from each parent, but it is a random
half. Assume that your ggp had only 8 genes, A-H. Assume further
that your gp inherited 4 of them, genes A-D, 50%. Your parent would
have inherited 4 genes >from your gp. They might have been A-D, in
which case your parent would have 50% Ashkenazi genes. If your parent
inherited genes E-H, he would have no Ashkenazi genes. Either result
is possible, though neither is the most statistically likely. It is
more likely that your parent inherited 3, 2, or 1 Ashkenazi genes.
The same calculus applies to your inheritance >from your parent, which
is why it appears that you have more Ashkenazi dna than you "should"
San Diego CA 92110 U.S.A.