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.

Example Input: [112.026, 20.03, 73.595, -24.957, 185.718, 36.43, 206.024]
Example Output: 86.981

Example Input: [226.287, 114.252, -53.47, 8.606, 234.708, -31.872, 163.615]
Example Output: 94.589

Example Input: [208.812, 24.785, 213.779, 188.42, 88.614, 128.372, 239.569, -64.778, 125.207]
Example Output:
128.087