- The Variance

Oops, try again. grades_variance([5, 6, 9, 3, 6, 9, 6]) returned 5500.2669061708 instead of the expected: 3.9183673469

```
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(grades)
print 'average:' + str(average)
variance=0
for score in scores:
variance+=((average-score)**2)
print 'variance: ' + str(variance)
print 'len: ' + str(len(scores))
return variance/float(len(scores))
print grades_variance(grades)
```