[BiO BB] Mean and Standard deviation

[Frenz, Christopher]

SD calculations involve the sample size as one of the variables.  This is likely what is causing the change in SD, since you are reducing the the sample size when you remove the two sets of endpoints.

Chris


-----Original Message-----
From: bio_bulletin_board-bounces+christopher_frenz=nymc.edu at bioinformatics.org on behalf of Subhash Agarwal
Sent: Tue 2/21/2006 12:03 AM
To: bioinformatics.org
Subject: [BiO BB] Mean and Standard deviation
 
Dear Forum Memebers
   
  I have a dataset with 394 data points. The frequecy distribution of which is as follows:
   
                0-0.02  85    0.02-0.04  63    0.04-0.06  51    0.06-0.08  39    0.08-0.1  36    0.10-0.12  24    -0.12-0.14  21    0.14-0.16  19    0.16-0.18  13    0.18-0.2  10            >0.20            33
   
  The mean and SD of the data is 0.0842 and 0.0853. But when the data points from 0-0.02 and > 0.2 are removed and the mean and SD is calculated it is found that mean doesnt change much (0.0819) but SD does (0.0472). My query is what can I interpret from this regarding the data.
   
  If any of the forum members feels that this question should be addressed to some other place do let me know.
   
  Thanks
  Subhash

				
---------------------------------
 Jiyo cricket on Yahoo! India cricket
Yahoo! Messenger Mobile Stay in touch with your buddies all the time.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: winmail.dat
Type: application/ms-tnef
Size: 3509 bytes
Desc: not available
URL: <http://www.bioinformatics.org/pipermail/bbb/attachments/20060221/989ae434/attachment.bin>