Could u please help me to understand what is the mistake in the code? Thanks.

9. How is Everybody Doing?

Error Message

Oops, try again. 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]
}
def average(numbers):
total=0
total = sum(numbers)
total = float(total)
total = total/ len(numbers)
return total
def get_average(student):
homework =average(student["homework"])
quizzes =average(student["quizzes"])
tests =average(student["tests"])
sonuc=0.1*homework+0.3*quizzes+0.6*tests
return sonuc
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"
def get_class_average(students):
results=[]
for eachstudent in students:
results.append(get_average(students))
return average(results)
```