Weighted Average

[Guest]

I am trying to get some square footages...I have a series of lengths in one
column, and a series of widths in the next...I want to get an average width
and multiply it by the sum of the lengths...the formula is
roughly...(A1*B1)/AxA28+B28)/Ax...where Ax is the sum of A1:A28 in this
case...that formula obviously does not work...is there an easier way to enter
this than to individually plug in every cell in a huge equation?...does this
make any sense...thank you for any and all help...

 

[BenjieLop]

I am trying to get some square footages...I have a series of lengths i
one
column, and a series of widths in the next...I want to get an averag
width
and multiply it by the sum of the lengths...the formula is
roughly...(A1*B1)/AxA28+B28)/Ax...where Ax is the sum of A1:A28 i
this
case...that formula obviously does not work...is there an easier way t
enter
this than to individually plug in every cell in a huge equation?...doe
this
make any sense...thank you for any and all help...

If Column A is where the lengths are entered and Column B is where th
widths are entered, your formula is

=AVERAGE(B1:B28)*SUM(A1:A28

where

*average(B1:B28)* is the average of the widths in Column B &
*sum(A1:A28)* is the sum to the lengths in Column A

Hope this is what you are looking for.


Regards

 

[Bob Phillips]

From the title I would have guessed

=AVERAGE((A16:A18)*(B16:B18))

which is an array formula, and is committed with Ctrl-Shift-Enter

but from the description I think you might mean

=SUMPRODUCT(A16:A18,B16:B18)/SUM(A16:A18)

which is not an array formula

--

HTH

RP
(remove nothere from the email address if mailing direct)