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 = float(sum(numbers))

result = total / float(len(numbers))

return result

def get_average (student):

homework= average(student["homework"])*0.1

quizzes= average(student["quizzes"])*0.3

tests= average(student["tests"])*0.6

return homework+quizzes+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"

print get_letter_grade( get_average(lloyd))

def get_class_average(students):

results=[]

for student in students:

get_average(student)

results.append(get_average(student))

return average(results)

print get_class_average([lloyd, alice, tyler])

result = get_class_average([lloyd, alice, tyler])

print get_letter_grade(result)

please help

it says Oops, try again. One of the following is missing or broken when we tried to use it: alice, lloyd, tyler, students, get_class_average, get_letter_grade