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: [-74.139, -62.711, 83.1, 211.243, -2.696, 30.722, 79.262, 230.335]
Example Output: 61.89

Example Input: [-86.423, 157.154, 69.563, -67.516, 147.66, 216.018, 213.404]
Example Output: 92.837

Example Input: [235.153, -94.289]
Example Output:
70.432