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.

[-65.295, 113.842, -82.683, 235.996, 143.686, 31.127, 135.386, 217.657, -87.331]
71.376

[-90.211, -60.08, 99.87, 18.704, 197.269, 173.722, 168.875]
72.593

[116.074, 213.452, 86.981]

138.836