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: [94.752, 94.081, 191.426]
Example Output: 126.753

Example Input: [-64.231, 200.235, -9.547, -98.817, 222.577, 12.8, 214.705, 122.883, 216.246, 113.126]
Example Output: 92.998

Example Input: [81.461, 239.025, -40.541, 93.384, 21.785, 229.96, 77.899, 201.861, 198.579]
Example Output:
122.601