Solved

test to see if an number is greater than one standard deviation from mean in Excel

Posted on 2013-11-13
4
392 Views
Last Modified: 2013-11-13
Experts,

Does anyone know how  code a formaul in Excel test to see if a number is greater than one standard deviation from the mean?
0
Comment
Question by:morinia
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
4 Comments
 
LVL 50

Accepted Solution

by:
barry houdini earned 500 total points
ID: 39646274
Well, if you have a range of numbers like A1:A10 then you can get standard deviation of those numbers with

=STDEV(A$1:A$10)

......so if you want to test whether any specific number, like A1 is greater than one standard deviation from the mean use

=A1>AVERAGE(A$1:A$10)+STDEV(A$1:A$10)

that will give you TRUE or FALSE

See attached example - press F9 to generate new numbers

regards, barry

PS this version only gives you numbers at the top end - if you want to find any numbers that are more than 1 standard deviation away from the mean (either higher or lower) you can use this version

=ABS(A1-AVERAGE(A$1:A$10))>STDEV(A$1:A$10)
STDEV.xlsx
0
 

Author Comment

by:morinia
ID: 39646299
Barry,

This is great.  Is there any way to eliminate the high end and low end numbers when calculating the standard deviation?

I am able to do it when calculating the average by using this formula.

=(SUM(C29:G29)-MAX(C29:G29)-MIN(C29:G29))/(COUNT(C29:G29)-2)
0
 
LVL 50

Assisted Solution

by:barry houdini
barry houdini earned 500 total points
ID: 39646332
For a small range of numbers like that you could use this formula

=STDEV(SMALL(C29:G29,{2,3,4}))

or for any range

=STDEV(SMALL(range,ROW(INDIRECT("2:"&COUNT(range)-1))))

confirmed with CTRL+SHIFT+ENTER

Note: for the average without highest and lowest values you can simplify your version by using TRIMMEAN function, i.e.

=TRIMMEAN(C29:G29,2/COUNT(C29:G29))

regards, barry
0
 

Author Closing Comment

by:morinia
ID: 39646500
Awesome.  Thanks.
0

Featured Post

[Webinar] How Hackers Steal Your Credentials

Do You Know How Hackers Steal Your Credentials? Join us and Skyport Systems to learn how hackers steal your credentials and why Active Directory must be secure to stop them. Thursday, July 13, 2017 10:00 A.M. PDT

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In Part II of this series, I will discuss how to identify all open instances of Excel and enumerate the workbooks, spreadsheets, and named ranges within each of those instances.
This article describes how you can use Custom Document Properties to store settings and other information in your workbook so that they will be available the next time you open the workbook.
This Micro Tutorial will demonstrate in Microsoft Excel how to add style and sexy appeal to horizontal bar charts.
I've attached the XLSM Excel spreadsheet I used in the video and also text files containing the macros used below. https://filedb.experts-exchange.com/incoming/2017/03_w12/1151775/Permutations.txt https://filedb.experts-exchange.com/incoming/201…

734 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question