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.

[-66.387, 135.639, 182.921, 175.573, 105.67, -29.751, 156.67, 83.119, 19.538]
84.777

[18.155, 114.069, 197.871, -99.696, 201.18]
86.316

[78.678, -33.174, 229.345, 176.337, -36.88]

82.861