hello, Thank you to understand that this is not a homework! I have to evaluate the uncertainty of a measurement but the baseline is also with uncertainty (correlation). I would like to have some ideas or suggestions on the best way to evaluate the uncertainty. Here is the problem: We have an aqueous solution for which, the density D is temperature T and concentration X dependent: D = a + bX + cX² + T (d + eX) This expression is an experimental correlation (from the literature) whose accuracy is 2%. T: temperature; absolute uncertainty = 0.5°C We measure our solution temperature T and density D. We solve the above correlation equation in order to find the concentration X. WHAT IS THE UNCERTAINTY OF THE OBTAINED VALUE X? Is it correct to consider that the uncertainty of “variable” D is 2%? Thank you.