First of all, let me show my code that I wrote for calculating addition and its average.

```
def getMean (myList):
    sumVal = 0
    countVal = 0

    for n in myList:
        sumVal = sumVal + n
        countVal = countVal + 1
    return sumVal/countVal

```

This is the successful code that can calculate addition and could get its average.
And if I print it out like below:

```
ans = getMean([1, 6, 9])
print(ans)

```

> 
> 5.333333333
> 
> 
> 

the number above will come out as result.

In this situation, I want to add standard deviation using `append`.

For example, like:

```py
stdVal = []
stdVal.append(3)

```

Where can I fit those statements in my previews code?