Experimentally verify that if you generate 9 numbers at a time between 0 and 1 and sort them, the first number will average out to 0.1, the second to 0.2, etc.

gistfile1.txt

// e.g. round(3.456, 1) -> 3.5
Number.prototype.round = function(v, a) {
  if (typeof a === 'undefined') {
    a = v;
    v = this;
  }
  if (!a) a = 0;
  var m = Math.pow(10,a|0);
  return Math.round(v*m)/m;
};

var n = 10000, l = {'1':[],'2':[],'3':[],'4':[],'5':[],'6':[],'7':[],'8':[],'9':[]}, i = 0, g = 9, j = 0;
for (i = 0; i < n; i++) {
  var ll = [];
  for (j = 0; j < g; j++) {
    ll.push(Math.random());
  }
  ll.sort();
  for (j = 0; j < ll.length; j++) {
    l[''+(j+1)].push(ll[j]);
  }
}
for (var x in l) {
  if (l.hasOwnProperty(x)) {
    var s = 0, m;
    for (i = 0, m = l[x].length; i < m; i++) {
      s += l[x][i];
    }
    l[x] = (s/m).round(3);
  }
}
console.log(l);