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.

[-86.423, 157.154, 69.563, -67.516, 147.66, 216.018, 213.404]
92.837

[182.34, 105.105, 248.658, 104.174, -98.917, -47.707, -61.048, 241.903, -34.659, 31.89]
67.174

[172.536, -11.071, 223.514, 84.104, -54.525]

82.912