I recently completed an experiment for university level physics and am currently doing the analysis of the data. This data has been transformed to fit a linear model and it fits this very well, with the line of best fit lying within all error bars. I need to provide estimate of the gradient and intercept as these have a physical interpretation. I was hoping to do a line of worst fit, the worst line that still fits all error bars. I can do this to some degree of accuracy by plotting the data by hand, but I was wondering if there was a more systematic approach using any statistical package? I have access to SPSS, Excel and R, though I am not that familiar with the latter. Though I suppose I could always download a trial version of other packages. So is there anyway to fit lines of worst fit? Thanks for any help you can provide.