In this task you will be given a list of numbers and you need to find the mean (average) of that list. The mean of a list can be found by summing every number in the list then dividing the result by the size of that list. The output should be rounded to 3 decimal places.

Ex Input:
[94.752, 94.081, 191.426]

Ex Output:
126.753

Ex Input:
[155.467, -40.717, -24.529, -22.608, 38.752]

Ex Output:
21.273

Ex Input:
[-28.295, -24.828, -66.96, -12.108, -96.597, 110.99, 172.86, -18.752, 157.717]

Ex Output:
21.559