yogi_Compute Row By Row Moving Average (or Sum) Of Data In Column A For Specified Number Of Items

                                          Google Spreadsheet   Post  #1408
Yogi Anand, D.Eng, P.E.      ANAND Enterprises LLC -- Rochester Hills MI     www.energyefficientbuild.com.   Nov 02, 2013
question by mep2hu (http://productforums.google.com/forum/?zx=pmz6oo65xaw#!mydiscussions/docs/mgfGOYDzAQw)
Array Formula Moving Average
Consider this spreadsheet:

Date	Value	Average 10 day
1/6/2013	78
1/7/2013	71
1/8/2013	67
1/9/2013	64
1/10/2013	62
1/11/2013	60
1/12/2013	60
1/13/2013	65
1/14/2013	65
1/15/2013	66
1/16/2013	65
1/17/2013	63
1/18/2013	63
1/19/2013	62
1/20/2013	61
1/21/2013	62
1/22/2013	60
1/23/2013	58
1/24/2013	59
1/25/2013	60
1/26/2013	61
1/27/2013	60
1/28/2013	60
1/29/2013	59

https://docs.google.com/spreadsheet/ccc?key=0Atrb4wVf_dsSdFc3LW9vcjFMaWhxLVdEUVByeUE4Y1E#gid=1

Is there an arrayformula that I can put in the shaded box (C11) that will calculate a 10-day moving average for the values in column B.

Average(B2:B9) can be copied down.   Arrayformula(Average(B2:B : B9:B) doesn't seem to work.

Thanks.

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hanks for the answers guys.   Yogi, I have included a link - perhaps it will help.

APL, I tried your formula and it gave an average for 11 rather than 10 - so I tried to adapt it for 10, and it works for all values but the first.

I use this a lot, so any additional help would be appreciated.

https://docs.google.com/spreadsheet/ccc?key=0Atrb4wVf_dsSdEtPYzgxZk91djIxWENLVTVvSENENWc#gid=0

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