```
`grades = [100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]
def print_grades(grades):
for grade in grades:
print grade
def grades_sum(grades):
total = 0
for grade in grades:
total += grade
return total
def grades_average(grades):
sum_of_grades = grades_sum(grades)
average = sum_of_grades / float(len(grades))
return average
def grades_variance(scores):
average = grades_average(scores)
variance = 0
for i in scores:
variance = ((average - i) ** 2.0)
variance = variance / len(scores)
return variance
print grades_variance(grades)`
```

error: Oops, try again. grades_variance([9, 5, 0]) returned 7.2592592593 instead of the expected: 13.5555555556

Help :<