I'm not sure that's working exactly as I was expecting. For example, if we look at only weight for Jan 3rd and 4th for Location A (the first 5 rows of data), we get:

Total weight for Location A for Jan 3rd = 120.6
Total weight for Location A for Jan 4th = 533.0
Average weight per day for these two days is then 326.8.

I may not have explained myself correctly in my first post. Does this make sense?

Thanks, DBY!