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: [149.037, 38.743, 27.996, 202.664, 131.973, 32.965, 177.298, -67.983, 120.683]

90.375