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.

[3.03, 107.892, 181.606, -95.674, -84.295, 40.666, 59.011, -27.334, 82.859, -86.426]
18.133