Your question is unclear and incomplete:
- What distribution do you want this random numbers to follow (uniform,
normal, or other)
- Is Z the mean of the distribution (which will probably depend on X &
Y0, or is it the observed sample average which means that the random
numbers will not be independent of each other?

Jerry

pinosan wrote:

I would like to use Excel to generate random numbers which:

a) are situated between values X and Y (so far no problem)

*AND*

b) yield a mean Z, which is different from the average of X and Y.

Could anyone help ?