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: [-71.118, 160.927, 230.116, -26.655, -4.297, 64.272, 72.304, 41.517, 242.068]

78.793