weighted average method of rainfall measuring

[engrsalah]

There are number of methods which can be employed for estimation of the areal
rainfall including:
•The Arithmetic average method,
•Weighted average method
•Thiessen polygon method.
•Kriging techniques. etc
can any one explain the weighted average method. its formula and solved example if possible? 

 

[milanov]

https://www.njstormwater.org/bmp_manual/NJ_SWBMP_5 print.pdf

https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044171.pdf

 

[TerryScan]

https://www.weather.gov/abrfc/map