Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I am trying to calculate a weighted average where the final answer is known, but the multiplier is not.

So I want to know is, if I have a formula such as $30x + 40.3y + 27.8z = 55$, where $x$, $y$ & $z$ will always add to 100%, what are the possible values of $x$, $y$, & $z$. Is there a simple way to do this in excel, or something similar? I would like something that would tell me all the possible combinations of $x$, $y$, and $z$.

Thanks!

share|improve this question
1  
There are an infinite number of combinations of x, y, and z. Are there any other restrictions on your variables? –  Simon Hayward Dec 7 '12 at 15:28

1 Answer 1

Unless you have a further restriction on your variables then they will be able to take an infinite range of values in $\mathbb{R}$.

We have two restrictions, the first one, and $x + y +z =100$, but two equations in three variables will always have one free variable.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.