title: Get the a unique median value out of list of several objects.
body: <p>I have this list of 3 objects which contain biomass values. I want to extract one unique value out this list which correspond to the median of all the forest biomass values inside the 3 objects. I think it is pretty straightforward but somehow could not manage to get there. Can someone help me out whith that? Thanks for your help.</p>
  
  <pre><code>dput(x)
  list(structure(c(3.37515461444855, 5.19044327735901, 3.22319519519806, 
  5.68365132808685, 2.36871695518494, 2.36871695518494, 3.63608360290527, 
  2.99963092803955, 10.2748856544495, 10.2748856544495, 16.4309034347534, 
  22.3492307662964, 12.4613256454468, 0, 2.03538191318512, 1.07113289833069, 
  21.3975343704224, 15.1670708656311, 4.22249209880829, 7.37385129928589, 
  14.4166820049286, 14.3547036647797, 0, 7.37385129928589, 7.05217242240906, 
  7.05217242240906, 3.68692564964294, 7.05217242240906, 6.73049354553223, 
  7.05217242240906, 3.67388677597046, 25.9837236404419, 45.9836235046387, 
  33.4825744628906, 1.5435653924942, 10.1114643216133, 45.6102886199951, 
  10.1114643216133, 31.958158493042, 45.2369537353516, 45.2369537353516, 
  18.6793632507324, 18.6793632507324, 21.7280540466309, 19.710410118103
  ), .Dim = c(45L, 1L), .Dimnames = list(NULL, "Forest_Biomass_2000")), 
      structure(c(14.4797344207764, 2.04780006408691, 0, 0, 13.7020168304443, 
      0, 0, 0.32373720407486, 22.9602508544922, 11.6327629089355, 
      0, 4.97857093811035, 5.25019407272339), .Dim = c(13L, 1L), .Dimnames = list(
          NULL, "Forest_Biomass_2000")), structure(NA_real_, .Dim = c(1L, 
      1L), .Dimnames = list(NULL, "Forest_Biomass_2000")))
  </code></pre>