I brought up the Bay Area in terms of the medium because someone moving from the Bay Area to Hawaii would have zero impact on the median population longitude. However, it would impact the mean population longitude
Just noting that since the Bay Area's pretty heavily populated, bringing in Puerto Rico (shifting the US median south by ~1.6 million people) takes the median from say Napa's latitude to, say Alameda's latitude (keeping in mind that there's also Louisville KY and other smaller non-SFBA towns in the same band of latitude).