new_contents: lloyd = {
      "name": "Lloyd",
      "homework": [90.0, 97.0, 75.0, 92.0],
      "quizzes": [88.0, 40.0, 94.0],
      "tests": [75.0, 90.0]
  }
  alice = {
      "name": "Alice",
      "homework": [100.0, 92.0, 98.0, 100.0],
      "quizzes": [82.0, 83.0, 91.0],
      "tests": [89.0, 97.0]
  }
  tyler = {
      "name": "Tyler",
      "homework": [0.0, 87.0, 75.0, 22.0],
      "quizzes": [0.0, 75.0, 78.0],
      "tests": [100.0, 100.0]
  }
  
  # Add your function below!
  def average(lst):
      sum = 0
      for item in lst:
          sum = sum + item
      return sum / len(lst)
     
  def get_average(student):
      sum = 0
      sum = sum + average(student["homework"]) * 0.1
      sum = sum + average(student["quizzes"]) * 0.3 
      sum = sum + average(student["tests"]) * 0.6
      return sum
     
  def get_letter_grade(score):
      if score >= 90:
          return "A"
      elif score >= 80:
          return "B"
      elif score >= 70:
          return "C"
      elif score >= 60:
          return "D"
      else :
          return "F"
         
  print get_letter_grade(get_average(lloyd))
  
  def get_class_average(lst):
      sum = 0
      for student in lst:
          sum = sum + get_average(student)
      return sum / len(lst)
     
  students = [lloyd, alice, tyler]
  
  avg = get_class_average(students)
  print avg
  print get_letter_grade(avg)
  
subject: Create gradeCalc.py