// refactored code
// first set of functions received from Jake
// sum function worked upon receiving; did not modify
var sum = function(array){
    var total = 0;
      for(var index in array)
        total += array[index];
    return total;   
}
 
// mean function worked upon receiving: did not modify
var mean = function(array){
  var sum = 0;
    for(var index in array){
      sum += array[index];
    }
  return sum / array.length;
}

// median fuction worked upon receiving: cleaned up code
function median(array){ // modified code: replaced var median = function(array) with current code
  array.sort(function(x,y) {return x - y}); // modified code: replaced sorted with array
  var middle = (array.length - 1) / 2; // modified code: changed var mid_index to var middle
  if(array.length % 2) 
    return array[middle]; 
  else 
    return (array[Math.floor(middle)] + array[Math.ceil(middle)]) / 2.0; 
}

// second set of functions received from Devin
// sum function worked upon receiving: did not modify code
function sum(array) {
	var sum = 0;
	for (var i=0; i<array.length; i++){
		sum += array[i];
	}
	return sum;
} 

// mean function worked upon receiving: removed one line of code
function mean(array) {
	var mean = 0;
	for (var i=0; i<array.length; i++){
		mean += array[i];
	} //modified code: combined mean /= array.length and return mean;
	return mean /= array.length;
}

// median function didn't work upon receiving:  modified to work and cleaned up code 
function median(array) { //removed line of code
	array.sort( function(x,y) {return x - y}); //added function to sort numerically 
	var middle = Math.floor(array.length / 2) // modified to remove erroneous code
	if (array.length % 2)
		return array[middle];
	else 
		return (array[middle - 1] + array[middle]) / 2.0; // modified code: 2 to 2.0
}

/* user stories:
1. I need a way to add together a set of numbers and return the sum.
2. I need a way to return the average of a set of numbers.
3. I need a way to return the median of a set of numbers,
  making sure to return the middle number if the set of numbers is odd,
  or the division of the two innermost numbers if the set is even.
*/