# Thread: Math wiz help neede..

1. ## 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...

2. 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!

3. 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..

4. >>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.

5. 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?

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