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.

[-40.246, -7.512, 174.245, -98.6]
6.972

[88.77, 109.102, -86.446, 207.301, 160.91, -12.956]
77.78

[-99.308, 73.801, 212.248, 101.199, 85.965, -30.919, -39.938, 173.864]

59.614