On Fri, 24 Apr 2015 21:52:47 +0100 Brian Barker <[email protected]> wrote:
> At 21:00 24/04/2015 +0100, Pete Nikolic wrote: > >I need to be able to select the last 3 in a series of cells that > >change on a weekly basis so in > >week 1: there would be 1 cell - no action > >week 2: 2 cells - no action > >week 3: 3 cells - sum three cells > >week 4: 4 cells - sum last three > >week 5: 5 cells - sum last three > >and so it goes on for 8 weeks always just summing the last 3 cells > >in the series then divide by 3 subtract 30 = result .. > > I'm guessing that you want separate results for each week, not just a > single result - so that in week 5, for example, you would have three > results, not one. Let's imagine your data is in column A, starting in > A1. In B3, insert: > =AVERAGE(A1:A3)-30 > and fill down the column. > > If you want to suppress the display in B cells for which there is not > yet an A-cell vale, try something like: > =IF(A3=0;"";AVERAGE(A1:A3)-30) > > I trust this helps. > > Brian Barker > > Hi Brian ok lets see .. if we start as will be the case C3 will contain say 50 (the actual dates are of little importance ) a month later C5 will be say 47 and so on every month the next cell would be C7 then C9 then C11 what i need is to be able to automatically pick the last 3 cells containing data so when C9 is filled in then it needs to automatically choose C9 C7 C5 and add them then divide by 3 then subtract a variable defined on the day .. Hope this makes it a little clearer Thanks Pete . -- Illegitimi non carborundum . ro for the purists out there Noli nothis permittere te terere. -- To unsubscribe e-mail to: [email protected] Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/users/ All messages sent to this list will be publicly archived and cannot be deleted
