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.
[195.092, 151.243, -65.513, 55.009, -76.715, 113.276, 233.246, -91.18, -2.125]