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: [197.167, -39.617, 9.231, 158.841, 147.656, 169.999, -27.818, -60.471, -51.856, 8.285]

51.142