I'm currently working on a research assignment an I'm trying to determine whether a dependent variable like "percentage of correct answers" would be considered interval or ratio data. I was originally thinking ratio because it does seem like there would be a true zero (i.e. getting 0% correct), but I keep finding mixed results online. Plus, I know percentages can be tricky in this sort of situation. Any advice?
All percentages are ratios: the percentage of correct answers is the ratio of correct answers to total answers.