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: [163.905, 170.242, 94.071, 50.277, 218.562, -99.48, 180.404, -95.86, -43.816]

70.923