i get this error

Oops, try again. median([4, 5, 5, 4]) returned 5.0 instead of 4.5

I tried to change my / 2 into a / 2.0 as i need a float for the answer. I change all the division to floats and get another error

Oops, try again. median([4, 5, 5, 4]) resulted in an error: list indices must be integers, not float

im confused pls help me =[

```
def median(lst):
new_lst = sorted(lst)
lenth = len(new_lst)
if lenth % 2 == 0:
return (new_lst[lenth/ 2] + new_lst[lenth / 2]) / 2.0
else:
return new_lst[lenth/ 2]
```