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: [2.994, 206.185, -78.434, 75.704, 214.018, -58.807, -3.311, 145.248, 203.983, 184.978]

89.256