```
Traceback (most recent call last):
File "python", line 57, in <module>
File "python", line 53, in get_class_average
File "python", line 28, in get_average
TypeError: string indices must be integers, not str
```

My code looks like this (starting at line 27):

```
def get_average(student):
homework = average(student["homework"])
quizzes = average(student["quizzes"])
tests = average(student["tests"])
return (0.10 * homework) + (0.30 * quizzes) + (0.60 * tests)
def get_letter_grade(score):
grades = ["A", "B", "C", "D", "F"]
if score >= 90 :
return grades[0]
elif score >= 80 :
return grades[1]
elif score >= 70 :
return grades[2]
elif score >= 60 :
return grades[3]
elif score <= 60 :
return grades[4]
print get_letter_grade(get_average(lloyd))
students = ["Lloyd", "Alice", "Tyler"]
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(students)
print get_letter_grade(get_class_average(students))
```

Thank you!