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: [75.0, 101.313, 116.392, -0.366, 212.221, 138.735, 204.051, 207.851, 246.71]

144.656