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: [78.677, 204.118, -84.633, -66.793, 107.19, 20.363, 242.345, 151.362, 104.823, 227.314]

98.477