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: [208.988, -1.509, 123.136, -17.614, -52.895, 206.354, 46.43, 104.985, 181.221, 46.689]

84.578