Definition: 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.
Input: [31.269, 35.659, 185.166, 161.063, 100.801, 160.3, -67.091, 245.872, -12.512, -42.455]

79.807