1. The problem statement, all variables and given/known data Been given a problem where a force (F) is applied on a circular area (m2). If the percentage uncertainty of the force is 8% and the percentage uncertainty of the radius is 3%, what is the percentage uncertainty of the obtained value pressure? 2. Relevant equations I know that pressure equals force over area and to find the area it is πr2. Anyway to work the percentage out? 3. The attempt at a solution I assume you don't just 'add' the percentage uncertainties in this case. So far see that 8% over π3%2 would be the equation to work this out.