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: [154.314, -70.679, 147.938, 180.23, 193.971, 101.863, -36.597, 86.231, -31.851, 58.139]

78.356