You should really specify that the quiz relates to US states, rather than countries of the world. I spent a whole minute typing Monaco, Andorra, Liechtenstein etc.
For Providence to account for 98% of Rhode Island's population, you must be counting more than the city proper. But if you count more than the city proper population of Honolulu, it seems like it would account for more than 52% of the population of Hawaii and therefore make this list.
And the Census Bureau's population for the Urabnized Area of Providence is more than the entire population of Rhode Island because it includes urban population in Massachusetts and extends over to Fall River and Attleboro.