I have two sets of data: A and B. Each is represented by a mean and a standard deviation. I want to generate a ratio: A/B and be able to accommodate the variability from each group in the ratio. What formula should I use?

My guess is that if C=A/B then:

(

*d*C/C)2=(

*d*A/A)2+(

*d*B/B)2

where

*d*C,

*d*A and

*d*B are the St. Dev, and my little 2 means square

I'd be really grateful for any help any one can give!