Definition: 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.
Input: [208.015, -87.163, -91.175, 148.043, 222.065, 171.829, -64.682, -6.178, -27.617, -86.023]

38.711