I am trying to do the last exercise where I am being asked to print out the result of "get_class_average" and "get_letter_grade". When I run the code, I get this error:

Traceback (most recent call last):

File "python", line 55, in

NameError: name 'students' is not defined

Here is my code.

```
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)

length = len(numbers)

new = total / length

return new

def get_average(student):

homework = average(student["homework"])

quizzes = average(student["quizzes"])

tests = average(student["tests"])

return (homework * .1) + (quizzes * .3) + (tests * .6)

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(students)

print get_letter_grade(get_class_average(students))