Averaging every xx'th value in a series

[Vidcapper]

I know this must've been answered before here, but I would be grateful
if someone could post a refresher.

TIA.

 

[Claus Busch]

Hi Paul,

Am Fri, 13 Jun 2014 17:39:58 +0100 schrieb Vidcapper:

I know this must've been answered before here, but I would be grateful
if someone could post a refresher.

every third row in A1:A25 (3,6,9,...):
=SUMPRODUCT((MOD(ROW(1:25),3)=0)*A1:A25)/SUMPRODUCT(--(MOD(ROW(1:25),3)=0),--(A1:A25<>""))

Every third row starting with the first in A1:A25 (1,4,7,..):
=SUMPRODUCT((MOD(ROW(1:25),3)=1)*A1:A25)/SUMPRODUCT(--(MOD(ROW(1:25),3)=1),--(A1:A25<>""))


Regards
Claus B.

 

[Vidcapper]

Hi Paul,

Am Fri, 13 Jun 2014 17:39:58 +0100 schrieb Vidcapper:


every third row in A1:A25 (3,6,9,...):
=SUMPRODUCT((MOD(ROW(1:25),3)=0)*A1:A25)/SUMPRODUCT(--(MOD(ROW(1:25),3)=0),--(A1:A25<>""))

Every third row starting with the first in A1:A25 (1,4,7,..):
=SUMPRODUCT((MOD(ROW(1:25),3)=1)*A1:A25)/SUMPRODUCT(--(MOD(ROW(1:25),3)=1),--(A1:A25<>""))


Regards
Claus B.

Thank you.