This is what I have when I get an error message

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)

av = total / len(numbers)

return av

def get_average(student):

homework = average(student[‘homework’]) * 0.1

quizzes = average(student[‘quizzes’]) * 0.3

tests = average(student[‘tests’]) * 0.6

sum = homework + quizzes + tests

return sum

def get_letter_grade(score):

if score >= 90.0:

return 'A’

elif score >= 80.0:

return 'B’

elif score >= 70.0:

return 'C’

elif score >= 60.0:

return 'D’

else:

return ‘F’

print get_letter_grade(lloyd)

def get_class_average(class_list):

results = []

for student_item in class_list:

final = get_average(class_list)

results.append(final)

return average(results)

the error says “get_class_average([alice]) resulted in an error: list indices must be integers, not str”