This is a really simple problem once you understand how to solve it, and that's what I'm going to show you! :)
When calculating the mean (average) of multiple numbers, your first step is to add the numbers together.
190,258.50 + 152,698.00 + 122,753.00 + 220,523.00 + 231,951.00 = 918,183.50
Then you take the sum of your numbers, and divide the sum by the amount of numbers added, which in your case, is 5.
918,183.50/5 = 183,636.70
The average of these numbers is $183,636.70
Feel free to message me or comment with any questions you have about this.