Perhaps you can merge the SAS question I asked here as it is on the same topic?
After a conversation on that thread I have a more basic question. You have a state mean, based on a sample. You want to know if (from a sample) a region in that state's mean is close enough to the state mean to be said to be the same population. Is there a t-test that even addresses this? I thought a one sample t-test would, but I am less sure now. I am confident an independent t test won't work (they are not impendent) and it would not be a paired t-test because the region would be a subset of the state numbers. Not the same units exactly.