user: Question: How much Longitude has a County of nelson, and a Latitude larger than 47.980183?
Columns: ['Township', 'County', 'Pop. (2010)', 'Land ( sqmi )', 'Water (sqmi)', 'Latitude', 'Longitude', 'GEO ID', 'ANSI code']
Types: ['text', 'text', 'real', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: ['Ibsen', 'Richland', 105.0, 36.238, 0.0, 46.325995, 96.841226, 3807739700.0, 1036840.0]
SQL:

assistant: SELECT SUM("Longitude") FROM "Table" WHERE "County" = 'nelson' AND "Latitude" > 47.980183;