According to the 1790 census, north carolina has more residents than massachusetts. yet, massachusetts has more representatives in congress than north carolina. what does this tell us about the impact of the three-fifths compromise?

This tells you that there are more slaves in North Carolina than in Massachusetts. That is because according to the compromise, a slave is worth 3/5 of a man, so even though it has more residents, many of them are slaves and when they are all added up you get a number that is not as relevant for the representatives election.