Generate two distirbutions with same mean and variance

[vickyho1008]

How can I generate two distributions with the same mean and variances
but with totally different dispersion like the one shown on th
attachement? thank

 

[Michael R Middleton]

vickyho1008 -

How can I generate two distributions with the same mean and variances, but
with totally different dispersion like the one shown on the attachement?
thanks <

If two distributions have the same variances, they have the same dispersion.

If you want two distributions with the same mean, e.g., 100, and different
variances, e.g., 10 and 20, you could generate normally distributed
distributions using =NORMINV(RAND(),100,10) in one group of cells and
=NORMINV(RAND(),100,20) in another group.

- Mike

www.mikemiddleton.com

 

[Michael R Middleton]

If you want two distributions with the same mean, e.g., 100, and different

variances, e.g., 10 and 20, you could generate normally distributed
distributions using =NORMINV(RAND(),100,10) in one group of cells and
=NORMINV(RAND(),100,20) in another group. <

Oops!

That should have been "... different standard deviations, e.g., 10 and 20
...."

The third argument of NORMINV is a standard deviation, not a variance.

- Mike

www.mikemiddleton.com

 

[Myrna Larson]

Hi, Mike:

Thanks for (inadvertently) reminding me of the NORMINV function. I just posted
some VBA code to generate normally distributed RN's but it is probably lots
slower than the built-in function.

Myrna Larson

 

[Jerry W. Lewis]

I wouldn't use use NORMINV for generating RVs in any version prior to 2003

http://groups.google.com/groups?selm=411E1DEE.9030702@no_e-mail.com

Jerry