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

```
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)
total = total / len(numbers)
return total
def get_average(student):
homework = float(average(student["homework"]))
quizzes = float(average(student["quizzes"]))
tests = float(average(student["tests"]))
homework = float(homework) * 0.1
quizzes = float(quizzes) * 0.3
tests = float(tests) * 0.6
whole = tests + quizzes + homework
return whole
def get_letter_grade(score):
if score >= 90:
return "A"
elif 80 <= score < 90:
return "B"
elif 70 <= score < 80:
return "C"
elif 60 <= score < 70:
return "D"
else:
return "F"
print(get_letter_grade(get_average(lloyd)))
def get_class_average(students):
results = []
for count in students:
results.append(get_average(students))
return average(results)
```