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: [6.75, 159.241, 2.768, 177.522, -26.097, -91.807, 84.681, 203.487, 149.677]

74.025