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: [169.131, -79.809, 119.898, 174.146, -1.167, 89.734, 155.318, -26.905, 182.476, 164.085]
Example Output: 94.691

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

Example Input: [-11.211, 9.955, 208.942, 124.097, 118.282, 65.001]
Example Output:
85.844