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: [0.401, 29.557, -52.715, -10.743, 150.825, -72.887, 57.093, 232.129, 247.699]

64.595