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: [181.615, 237.938, 100.237, 229.449, 219.442, 157.359, 78.05, -50.553, 246.052]

155.51