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(numbers):

total=sum(numbers)

total=float(total)

average=total/len(numbers)

return average

def get_average(student):

homework=average(student["homework"])

quizzes=average(student["quizzes"])

tests=average(student["tests"])

return 0.1*homework + 0.3*quizzes + 0.6*tests

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"

students = [lloyd, alice, tyler]

def get_class_average(students):

results=[]

for student in students:

results=results.append(get_average(student))

print results

return average(results)

Error:**Oops, try again. get_class_average([alice]) resulted in an error: 'NoneType' object is not iterable**