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 Q]: [-20.155, -42.404]
[EX A]: -31.28

[EX Q]: [245.271, 40.965, 133.913, 212.104]
[EX A]: 158.063

[EX Q]: [-11.876, 131.743, -47.213]
[EX A]:
24.218