# Math wiz help neede..

• 09-27-2004
vasanth
Math wiz help neede..
Ok I know how to calculate the Standard Deviation of say 10 given values....... But can some on etell mehow i can calculate the reverse...

Say i Have a standard devaition of 0.316 now I would like to generate say 10 values that give this deviation......

Thanx for any help...
• 09-27-2004
axon
I doubt that it is possible; the same standard deviation could be obtained from an infinity of sets of ten numbers...you will never get the exact 10 that this deviation was used for. There might be a generalization about these infinite number of sets however... you need some more info vasanth.

I might be wrong, but right know I don't see a way - but I have statistics today and I just might ask my prof! :)
• 09-27-2004
vasanth
well its fine as long as I get any 10 numbers within a given range that gives the same deviation...

I dont care what those numbers are as long as they satisfy the deviation..
• 09-27-2004
axon
>>I dont care what those numbers are as long as they satisfy the deviation..<<

ahh, well that changes things a bit...when I get home today I'll try to work something out.
• 09-27-2004
exluddite
Well, standard deviation is the square root of the variance, so I suppose you could plug in variables and try to solve for it? First off you'd have to find a mean.

(x-mean)'+(y-mean)'+(z-mean)'
--------------------------------------- = variance (' is "squared")
3

Trying to get 10 or so numbers crunced out of that is beyond me.

You do know that falsifying data is frowned upon, don't you? :D
• 09-27-2004
vasanth
Quote:

Originally Posted by exluddite
You do know that falsifying data is frowned upon, don't you? :D

lol.. actually I need this data to simulate phone calls...(acually call holding time).. and the input given by the user is just the deviation and I need to do the rest...

Hope some one here can come up with a solution on how to calculate it..