The result I get is as follows:

Lloyd:

80.55

B

Alice:

91.15

A

Tyler:

79.9

C

Class average:

None

None

None

83.8666666667

None

None

None

C

None

This is a "correct" result... but I must ask: Why do I get a total of seven lines of "none"?

And why do my code print a class average of "C" when it should be "B"?

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]
}
students = [lloyd, alice, tyler]
def average(numbers):
total= float(sum(numbers))
result = total / len(numbers)
return result
def get_average(student):
homework = average(student["homework"])
quizzes = average(student["quizzes"])
tests = average(student["tests"])
return 0.1*homework + 0.3*quizzes + 0.6*tests
def get_letter_grade(score):
score = get_average(student)
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 student in students:
print results.append(get_average(student))
return average(results)
for student in students:
print student["name"]+":"
print get_average(student)
print get_letter_grade(student)
print " "
print "Class average:"
print get_class_average(students)
print get_letter_grade(get_class_average(students))
```