Posted by April on Sunday, January 24, 2010 at 7:37pm.
How do I find a variance for a set of numbers {1,16,8,17,12}
I got that variance34.2, but I'm unsure. Any help? Thanks.

math  Reiny, Sunday, January 24, 2010 at 8:16pm
look at his page.
http://davidmlane.com/hyperstat/A16252.html 
Reiny  April, Sunday, January 24, 2010 at 8:25pm
I looked at that page and did my problem according to the example, but the answer I got wasn't even a choice. Can you help al ittle more please?

math  Reiny, Sunday, January 24, 2010 at 8:36pm
did you get a mean of 10.8 ?
My squared differences were:
96.04, 27.04,7.84,38.44,1.44
that sum/5 = 34.16 which is the variance^2
so the variance = √34.16 = 5.845
notice that there is difference in the calculation depending on whether you divide by N or N1.
Your text or your course should tell you which method to use. 
math  April, Sunday, January 24, 2010 at 8:54pm
No. I thought mean was adding up the numbers and then dividing by how many numbers.
So .51+.44+.04+.01=1 divided by 4=.25 
math  Reiny, Sunday, January 24, 2010 at 9:51pm
(1 + 16 + 8 + 17 + 12)/5 = 10.8
mmmmh?
where did you get your numbers from ????