Apply value based on calculation

Have facts table:

Department; Facility; Date; Value

Have a Table that needs to assign a weight based the daily averge of the value

Departement; Facility; Date; Daily Avg; Weight

I need to assign the weight to the daily average for each facility a department line for each day.

So if Department A; Facility XXX; on date 1/1/21 had a daily average of 5 assign the appropriate weight in the 2nd table.

My facts table is about 2m records.