I am analyzing a dataset. Each row corresponds to a participant who answered a questionnaire. Each participant is assigned a score based on their answers. I calculated the average score for each regional subgroup and I am interested in a statistical test that would suggest whether some regional subgroup's average score differs significantly from the national average. I am interested in a test whose assumptions regarding the distributions are minimal (for instance, I am not inclined to assume that the distributions are normal). Any suggestions?
By the way, I am working on R.
Thank you!