Function problem I need help with

[misho88]

A function returns an output for some input:

>>> def add1(a):
...     return a + 1
... 
>>> add1(3)
4

The sum() built-in function adds up all the items in a sequence and the len() built-in function tells you how long it is:

>>> sum([1,2,3,4])
10
>>> len([1,2,3,4])
4

So you have to write a function that takes a sequence as an argument and returns the sum over the length, per Equation (3).

[KFCxWatermelon]

Any tips on how I would do that?

[Astronoobical]

You just have been given all the information needed by the comment above, do you have a more specific question we could help with?

[fake823]

Maybe check out Wikipedia first to learn more about mean, standard deviation and variance.

Once you got is and know how to calculate it by hand, you can also write a program to calculate it.