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: [-15.327, 40.258, 209.752, -51.985, -28.634, -45.879, -63.239, 30.253, 180.29, 246.794]

50.228