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.
[114.303, 16.41, -39.174, 190.105, 242.352, -10.982, 70.776, 166.037]