I have a shapefile (.shp file) which defines a large number (several thousand) separate areas.
I also have an Excel spreadsheet which contains a large number of data points. Each data point consists of a latitude and longitude, and a "weight".
I want to determine, for each area in the shape file, the total weight of all the data points whose lat/long is in that area. I would prefer to have this information in a format that can be downloaded back into the Excel spreadsheet.
What is the best way to do this in QGIS?