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: [1.949, -70.019, 228.413, 102.775, -42.417, 138.511, 181.459, 15.207]

69.485