1. The problem statement, all variables and given/known data I am attempting to calculate a heat transfer across a medium with known material properties. I have the equation and all but one variable I have an exact answer for. I require the variance of my answer. 2. Relevant equations I know ALL variables (ie numerical value) except the the last h. So far, using some engineering parameters for the problem, I have estimated the value by taking 10% perturbations of the normal value of h (that is, the value is usually ~3.0 for this problem, and I have used logic to say that with the additional medium, the value will only affect AT GREATEST +/- 10%). I am unsure on how to actually calculate the value now. I have ran the equation in MATLAB using random number generator from 2.7-3.3 (10% perturbations) with 1E9 histories. Can I use this value to get the variance? (The output is not normal/gaussian). Thanks in advance!!