Here's an example making the rounds, originally from 2022: there is systemic bias in Americans' understanding of US national statistics about all kinds of subgroups:
https://yougov.com/en-us/articles/41556-americans-misestimat...
(Although, apparently the poll didn't ask how uncertain they were. The question was, "If you had to guess, what percentage of American adults...")
Did they really estimate that 30% of us adults live in New York?
I wouldn't be surprised if this were a general cognitive bias having to do with estimating proportions, and nothing to do specifically with minority groups.