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.

[245.2, 202.565]
223.882

[17.197, 152.985, 73.815]
81.332

[38.275, -86.61, -81.682, 203.89, 171.388]

49.052