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: [210.524, 246.743, -94.797, 192.394, -38.092, 218.801, 116.293, 42.303, 174.611, -9.802]

105.898