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.

[87.234, -30.861, 221.46, 120.15, -85.065, 67.024, 144.174, -64.546]
57.446

[172.084, 126.948, 90.757]
129.93

[-44.242, 55.956, 137.808, 184.661]

83.546