Summation of latest running 3 month total

[5oclock]

Hi everyone,

Sorry if this is a redundant posting but none of my posts seem to
appear...

It's my first time posting so I hope I am asking a not too basic
question...I tried searching for previous posting relating to this but
had no luck. My question is, I have a worksheet with months
starting in July 07 - June 08. Each month, as data become available,
a new month's of data will be added to the worksheet. If possible, I'd
like another column in my worksheet to always sum the lastest
three months. For the first couple of months, July 07 and August 07,
as there will be less than three month's worth of data, it would only
calculate what's available or display blank.

I hope that makes sense. Any help would be very much appreciated!!
Thanks so much!!!

TL

 

[Bob Phillips]

I gave you this

=SUM(N(OFFSET(C2,0,LARGE(IF(C2:N2<>"",COLUMN(C2:N2)-MIN(COLUMN(C2:N2))),ROW(INDIRECT("1:"&MIN(3,COUNT(C2:N2))))))))


and Tom Ogilvy gave you

=IF(COUNTA($F$2:$R$2)<3,"",SUM(OFFSET($F2,0,COUNTA($F$2:$R$2)-3,1,3)))


--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)