Goal Seek with two constraints

[Boom1]

Hi,

I'm trying to create a 12 month portfolio return stream where I know
the final return and I know the volatility. I want these two things,
the return and the volatility, to be my constraints and then I want
excel to randomly populate the 12M of data based upon that. I thought
goal seek was the way to go, but there's no where to put a second
constraint that I can see. Any suggestions?

 

[Tyla]

As you found, goal seek is designed to determine the value of one cell
based on existing formulas and optional user-specified constraints.
What you're asking for is not only beyond goal seek's capability, but
I believe any software's It's the "too many unknowns" issue. If you
could specify 11 month's of data, and you could use goal seek to last
unknown data point.
What you might try here is to use the RAND() function to create 11
months of data first, then goal seek the the last month's. The trick
here is that RAND() will recalc for each cycle of goal seek, making it
an infinte loop. To get around this, set up as many RAND() formulas as
you need to get your raw data, then copy those cells and do a "Paste -
Special / Values" back onto their original positions. You'll then have
a platform where Goal seek will work to determine the final cell's
value to meet your criteria.
I think.

/ Tyla /