Hi,

One solution is as follows. It assumes your data is sorted by product
and month. i.e. all product 100 (say) are listed underneath each other
and the months are ascending.

Use a helper column (say col F) if your data below is in cols A:E. It

Put the following formula in col F, and copy it down.

=IF(A10<A9,ROW(),F9)

This recognises when a product changes and results in the first row of
every change in product number being recorded for that product range.

Then your result formula in column E will be

=INDIRECT("C$"&ROW())/SUM(INDIRECT("$D$"&F10):INDIRECT("D"&ROW()))


This assumes your data starts in row 10. Adjust accordingly

HTH



On Thu, 6 Oct 2005 21:49:01 -0400, "J Shrimps, Jr."
wrote:

Need to divide a value in a column by a set of
running sum values in an adjacent column.
Data looks like this:

Product Month Bal RemBal Result
Calculation:
100 01 $10.00 $10 100%
10/10
100 02 $5.00 $15 25%
5/(10+15)
100 03 $2.00 $12 32%
12/(10+15+12)
.....
100 60 $9.00 $9 .01%
9/(10+15+12+ 60 months of balances )
400 01 $8.00 $8 100%
8/8
400 02 $5.00 $35 19%
5/(8+35)

now we have a new value and the month's sequence starts at 1 (01).

Currently the formula is:
row 8 =P8/SUM(R$7:R8)
row 9 =P9/SUM(R$7:R9)
row 10 =P10/SUM(R$7:R10)
row 11 =P11/SUM(R$7:R11)
in this case, the new product started at row 7 and might continue
for 60 more rows, or just 6 more, where the $R$7 part of the formula would
change again.

Usually, every 60 or so lines, (the # of months is different, depending
on the product) l have to re-start the formula (replacing $R$7 with $R$67
for example) so the SUM starts with month
0 and continues summing the contents of column R ,
until the last month for that product.

I have over 24,000 lines of this, it is getting very tedious to have to
re-copy the
formula every time there is a new product., making sure my formula captures
a running sum starting with the first month and divides the value in the
current row
into that running sum.
I'm planning on starting with "IF(P8<p7" - ie a new product has started
so start the forumula using the current row as the cell placed in the
formula
"sum($R$7", start the running sum up,
and divide the contents of the current row into the running sum values until
a new product, where the process starts all over again.
Is it possible to "Anchor" a running sum formula based on changing criteria
with some kind of vlookup/Sumif (or something else)?



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Richard Buttrey
Grappenhall, Cheshire, UK
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