text: var grades = [[89, 77],[76, 82, 81],[91, 94, 89, 99]];
  var total = 0;
  var average = 0.0;
  for (var row = 0; row < grades.length; ++row) {
     for (var col = 0; col < grades[row].length; ++col) {
        total += grades[row][col];
     }
     average = total / grades[row].length;
     print("Student " + parseInt(row+1) + " average: " +    
           average.toFixed(2));
     total = 0;
     average = 0.0;
  }