I don’t know that there is any way to calculate a median value of GDP/capita. You can look at income distributions and find a median income and compare that to a mean income, which could allow an estimation, but beyond that, GDP is an intrinsically composite number which cannot be easily (at all?) broken down to individual contributions. I assume income is what the parent commenter is basing the median-mean comparison on, but it’s kind of out of nowhere with no explanation.