1. The problem statement, all variables and given/known data The following data were obtained for trace elemental zinc in a particular sample of high purity (%Au> 99.99%). The results are given in mg Zn/ kg Au. 15.38, 15.17, 15.33, 14.88, 14.71, 15.42, 15.60, 15.22 Find the zinc content and the uncertainty at 95% confidence limit. 2. Relevant equations Molecular weight of gold: 196.966569 g mol-1 3. The attempt at a solution I found the average of all the values, then converted to mg of Zinc by multiplying the kg of Au. I'm not really sure on how to find the uncertainty at 95% confidence.