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.

[-15.843, 236.17, -79.922, -29.879]
27.632

[-84.771, 60.727, 165.566, 27.782, 159.929, 167.451, -64.15]
61.791

[221.211, 113.521, 219.842, -1.664]

138.228