code function for weighted average

[dennisli]

Good morning,
Right now I have one formula to get weighted average. If highlight this formula and hold and drag it to right, I can automatically to get each weighted average.
I tried to write function to express this formula in a simple way. Can you guys to help me to write a function code for this?
Thanks lot.
Dennis

Col A Col B

Year 12 24 36 48 60
1996 360 416 346 456 421
2002 400 500 430 230
2003 388 459 389
2004 390 466
2005 393
Weighted Average =SUM(C2:C6)/SUM(B2:OFFSET(B6,-B1/12,0))

 

[fairwinds]

Hi,

Does not

=AVERAGE(B2:B6)

work?

It disregard blanks.