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: [46.452, 143.923, -52.893, 205.541, -89.445, 243.088, -11.647, 29.934, 70.663]

65.068