Hi, All,

Stuck at 'Variance" for a whole day.Error message:-**File "python", line 24**

** int grades_variace(grades)**

** ^****SyntaxError: invalid syntax.**

But cant find any.Please help.My code is as below

```
grades = [100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]
def grades_sum(scores):
sum=0
for i in scores:
sum +=i
print sum
return sum
def grades_average(grades):
total= grades_sum(grades)
leng=len(grades)
if total%leng==0:
average=total/leng
else: average=total/float(leng)
print average
return average
def grades_variace(scores):
average=grades_average(scores)
variance=0
for i in scores:
variance +=(average-i)**2
return variance/float(len(scores)
print grades_variace(grades)
```