I am trying to figure out how to combine uncertainty (in x and y) into the standard error of the best fit line from the linear regression for that dataset. I am plotting units of concentration (x) versus del t/height (y) to get a value for the flux (which is the slope) I understand how to get the standard error of the best fit line, but that only gives the error in y in relation to the best fit line. Is there a good way to combine that error with the error from the individual measurements? For example: (x) (y) delt/h Conc. 0.00 563.84 2.39 568.77 3.53 566.64 11.03 572.59 The error in each y measurement is 9% When I do the linear regression, I get a slope of .71 and an error of .21 Is there a (relatively) simple way to propagate the 9% error into the regression error?