2:8
1:4
8:2
1:1/4
1:.25
there are two unit rates that could make sense: 1:4, because, using the ratio of 2:8, you divide 2 by 2, and 8 by 2, therefore making it equivalent, and 1: 0.25, or 1: 1/4, because you switch the ratio into 8:2 instead of 2:8, and divide each by 4. The first ratio makes more sense, because of the order, and how it doesn't need a fraction or decimal, but both could work.