Originally Posted by **wolfhound** Ok thanks,but I find that vertical offset method very hard to understand, is there easy explanation on how to use the standard errors to get the answer? |

There's one of my other favorite methods called

Propagation of Errors. However as you don't have any error measurements for f I'm pretty certain you can't use that method here. If you have a data set that, say, has errors in Vs as well as well as error measurements for f, then you can use a "chi-squared" fit. (I couldn't find a good link for this because there is something called a "chi squared test" in statistics. I couldn't get the search to work right.) The problem I see with chi-squared fit is that the theory is even harder than the least-squares fit.

Sorry that I can't be of any more help.

-Dan