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.

[131.164, 99.999, 138.488, 57.264, -40.069, -82.402, -42.836]
37.373

[89.226, 241.396, 7.011, 114.867, 113.075, 103.559, 83.142, 188.743, -27.33, 180.773]
109.446

[173.785, 76.621, 20.894]

90.433