The Elsmar Cove Wiki More Free Files The Elsmar Cove Forums Discussion Thread Index Post Attachments Listing Failure Modes Services and Solutions to Problems Elsmar cove Forums Main Page Elsmar Cove Home Page
Go Back   The Elsmar Cove Forum > Common Quality Assurance Processes and Tools > Quality Tools, Improvement and Analysis > Quality Assurance and Compliance Software Tools / Solutions > Excel .xls Spreadsheet Templates and Tools
Forum Username

Elsmar Cove Forum Visitor Notice(s)


Search the Elsmar Cove
Custom Search
Monitor the Elsmar Forum
Follow Marc & Elsmar
Elsmar Cove Forum RSS Feed  Marc Smith's Google+ Page  Marc Smith's Linked In Page   Marc Smith's Elsmar Cove YouTube Page  Marc Smith's Facebook Page  Elsmar Cove Twitter Feed
Elsmar Cove Groups
Elsmar Cove Google+ Group  Elsmar Cove LinkedIn Group  Elsmar Cove Facebook Group
Sponsor Links





Donate and $ Contributor Forum Access
Courtesy Quick Links

Links that Elsmar Cove visitors will find useful in your quest for knowledge:

Howard's
International Quality Services
Marcelo Antunes'
SQR Consulting
Bob Doering's
Correct SPC - Precision Machining

NIST's Engineering Statistics Handbook
IRCA - International Register of Certified Auditors
SAE - Society of Automotive Engineers
Quality Digest Portal
IEST - Institute of Environmental Sciences and Technology
ASQ - American Society for Quality
Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 1 votes, 5.00 average. Display Modes
  #1  
Old 2nd February 2007, 04:14 PM
T Dutton T Dutton is offline
Registered Visitor

 
Registration Date: May 2005
Location: USA New Hampshire
 
Posts: 10
Thanks Given to Others: 0
Thanked 0 Times in 0 Posts
Karma Power: 38
Karma: 10
T Dutton has less than 100 Karma points so far.
Question Does Excel STDEV calculate in 3 stdev (standard deviation)?

Does Excel STDEV calculate in 3 stdev?

Sponsored Links
  #2  
Old 2nd February 2007, 05:24 PM
Scott Catron's Avatar
Scott Catron Scott Catron is offline
True Artisan

 
Registration Date: Aug 2003
Location: Utah
 
Posts: 662
Thanks Given to Others: 53
Thanked 182 Times in 131 Posts
Blog Entries: 1
Karma Power: 112
Karma: 1309
Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.Scott Catron is appreciated, and has over 1300 Karma points.
Re: 3 standard Deviation in excel

If I'm interpreting the questions correctly - NO.

STDEV is one standard deviation - you'll have to multiply it by 3 in a formula somewhere.

__________________

I don't have a solution, but I admire your problem. -- Steven Wright
I'm a moderator here, so if you need help with something, feel free to ask.
Sponsored Links

  #3  
Old 2nd February 2007, 05:52 PM
Howard Lee's Avatar
Howard Lee Howard Lee is offline
Involved in Discussions

 
Registration Date: Sep 2006
Location: South Carolina
Age: 51
 
Posts: 107
Thanks Given to Others: 42
Thanked 60 Times in 33 Posts
Karma Power: 42
Karma: 862
Howard Lee is appreciated, and has over 700 Karma points.Howard Lee is appreciated, and has over 700 Karma points.Howard Lee is appreciated, and has over 700 Karma points.Howard Lee is appreciated, and has over 700 Karma points.Howard Lee is appreciated, and has over 700 Karma points.Howard Lee is appreciated, and has over 700 Karma points.Howard Lee is appreciated, and has over 700 Karma points.
Re: 3 standard Deviation in excel

In Excel STDEV yeilds one sample standard deviation. To get 3 sigma you need to multiply it by 3. Also, if you need the standard deviation of a population, you should use STDEVP instead.

__________________

Rock is hard but water is patient!!!
  #4  
Old 2nd February 2007, 06:33 PM
Statistical Steven's Avatar
Statistical Steven Statistical Steven is offline
Statistician

 
Registration Date: May 2005
Location: New Jersey
Age: 48
 
Posts: 963
Thanks Given to Others: 229
Thanked 351 Times in 244 Posts
Karma Power: 141
Karma: 4184
Statistical Steven is appreciated, and has over 1700 Karma points.
Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.
Send a message via Yahoo to Statistical Steven
Re: 3 standard Deviation in excel

Quote:
In Reply to Parent Post by Howard Lee View Post

In Excel STDEV yeilds one sample standard deviation. To get 3 sigma you need to multiply it by 3. Also, if you need the standard deviation of a population, you should use STDEVP instead.
I wish Microsoft would do away with the STDEVP function. It has no use. The difference is that STDEV divides by n-1 and STDEVP divides by n. Can anyone tell me when you would use STDEVP?

__________________

Steven Walfish
When in doubt, ask your company statistician!
  #5  
Old 2nd February 2007, 09:14 PM
Wesley Richardson's Avatar
Wesley Richardson Wesley Richardson is offline
Wes R

 
Registration Date: Jun 2004
Location: Indiana, USA
Age: 69
 
Posts: 162
Thanks Given to Others: 3
Thanked 57 Times in 30 Posts
Karma Power: 58
Karma: 885
Wesley Richardson is appreciated, and has over 700 Karma points.Wesley Richardson is appreciated, and has over 700 Karma points.Wesley Richardson is appreciated, and has over 700 Karma points.Wesley Richardson is appreciated, and has over 700 Karma points.Wesley Richardson is appreciated, and has over 700 Karma points.Wesley Richardson is appreciated, and has over 700 Karma points.Wesley Richardson is appreciated, and has over 700 Karma points.
Re: 3 standard Deviation in excel

Quote:
In Reply to Parent Post by Statistical Steven View Post

Can anyone tell me when you would use STDEVP?
Hi Statistical Steven,

It would be used if you had the entire data set. Although this is less common, there are a few cases: 1. The standard deviation of test scores for the entire number of students in a class. 2. The standard deviation of a part characteristic when you have measured all of the parts in the production run. Both cases would typically have a fairly small number in the population, such as less than 100 items.

I accept that if you have measured all of the population values, then you could graph the values and see how they are distributed.

Wes R.
  #6  
Old 3rd February 2007, 11:29 AM
Steve Prevette's Avatar
Steve Prevette Steve Prevette is offline
Deming Disciple

 
Registration Date: Feb 2004
Location: Aiken, SC
 
Posts: 2,260
Thanks Given to Others: 188
Thanked 1,290 Times in 705 Posts
Karma Power: 293
Karma: 12873
Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.
Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.Steve Prevette is appreciated, and has over 1700 Karma points.
Re: 3 standard Deviation in excel

Quote:
In Reply to Parent Post by Statistical Steven View Post

I wish Microsoft would do away with the STDEVP function. It has no use. The difference is that STDEV divides by n-1 and STDEVP divides by n. Can anyone tell me when you would use STDEVP?
I think I've also answered this on the ASQ board from a question there. But here goes:

The formula for sigma (STDEVP) is the maximum likelihood estimator for the population standard deviation. However, it is a biased estimator. If you only have a sample of the population (and consider - if the "future" is part of your population, you still only have a sample), STDEVP will have a bias in it. If you repeatedly sample from a population, you will notice that the average STDEVP values will not tend to match the actual population standard deviation. However, if you use STDEV (dividing by n-1), the average of the STDEV's will converge on the population standard deviation.

__________________

Steve Prevette
"A Passionate Statistician", ASQ CQE, ASQ Fellow
  #7  
Old 3rd February 2007, 10:10 PM
Tim Folkerts's Avatar
Tim Folkerts Tim Folkerts is offline
Super Moderator

 
Registration Date: Sep 2003
Location: Kansas, USA
Age: 51
 
Posts: 975
Thanks Given to Others: 29
Thanked 364 Times in 217 Posts
Karma Power: 152
Karma: 5869
Tim Folkerts is appreciated, and has over 1700 Karma points.
Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.Tim Folkerts is appreciated, and has over 1700 Karma points.
Re: Does Excel STDEV calculate in 3 stdev (standard deviation)?

I like what Steve said, but I want to make two minor points.
  1. sigma (STDEVP) would be the population standard deviation, not an estimate. When you have the full set, you don't need to estimate!
  2. I believe it is actually (STDEV)^2 that averages to (STDEVP)^2, not STDEV that average to STDEVP. That is, you take the variances calculated from the sample standard deviations and average them to get an unbiased estimate of the true variance.
Of course, all this is all WAY to esoteric for most people!

__________________

To wonder is to begin to understand.
  #8  
Old 3rd February 2007, 11:32 PM
Statistical Steven's Avatar
Statistical Steven Statistical Steven is offline
Statistician

 
Registration Date: May 2005
Location: New Jersey
Age: 48
 
Posts: 963
Thanks Given to Others: 229
Thanked 351 Times in 244 Posts
Karma Power: 141
Karma: 4184
Statistical Steven is appreciated, and has over 1700 Karma points.
Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.Statistical Steven is appreciated, and has over 1700 Karma points.
Send a message via Yahoo to Statistical Steven
Re: 3 standard Deviation in excel

Actually S^2 is the MLE for sigma squared...but that is not the point. If as Wes stated, you have the entire population, then why would you need to know the standard deviation. That is to say, any inferences to be made can be made from the data in the population. There are no confidence intervals that need to be calculated. I am stumped, regardless of the theoretical differences between sigma and S, why there is an application that someone would be using Excel for that requires the population stdev.

__________________

Steven Walfish
When in doubt, ask your company statistician!
Reply

Lower Navigation Bar
Go Back   The Elsmar Cove Forum > Common Quality Assurance Processes and Tools > Quality Tools, Improvement and Analysis > Quality Assurance and Compliance Software Tools / Solutions > Excel .xls Spreadsheet Templates and Tools

Do you find this discussion thread helpful and informational?


Bookmarks


Visitors Currently Viewing this Thread: 1 (0 Registered Visitors (Members) and 1 Unregistered Guest Visitors)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Forum Search
Display Modes Rate Thread Content
Rate Thread Content:

Forum Posting Settings
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Discussion Threads
Discussion Thread Title Thread Starter Forum Replies Last Post or Poll Vote
Overall and Within/Between STDEV - Why not the same? puck1263 Statistical Analysis Tools, Techniques and SPC 20 19th December 2012 12:17 AM
Pooled Standard Deviation - Mintab vs. Excel Validation2011 Using Minitab Software 15 7th August 2011 05:07 AM
How to Calculate Standard Deviation using Casio fx-95 MS Calculator? amanbhai Statistical Analysis Tools, Techniques and SPC 4 6th February 2008 04:49 AM
Mathematical difference between mean Deviation and Standard Deviation Abhijeet Statistical Analysis Tools, Techniques and SPC 3 11th July 2006 09:20 AM
About StDev in MINITAB13 Richard-jxb Using Minitab Software 3 16th December 2003 10:51 AM



The time now is 01:42 AM. All times are GMT -4.
Your time zone can be changed in your UserCP --> Options.


   


Marc Timothy Smith - Elsmar.com
8466 LeSourdsville-West Chester Road, Olde West Chester, Ohio 45069-1929
513 341-6272