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: [60.791, -35.898, 35.488, 161.144, 61.42, -81.454, 7.482, 166.826, -53.351]

35.828