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: [217.276, 69.181, 56.534, 10.472, 148.018, 38.673, -94.676, 241.577, -23.436, 45.907]
Example Output: 70.953

Example Input: [-41.714, 218.588, 49.769, 142.519, 179.776, -99.226, 224.69, 191.642]
Example Output: 108.256

Example Input: [218.036, 219.057, 63.243]
Example Output:
166.779