var numbers = new[] {1,2,3,4};
var averageNumber = numbers.Average();
Console.WriteLine(averageNumber);
// 2,5
This method calculates the average of enumerable of numbers.
var cities = new[] {
new {Population = 1000},
new {Population = 2000},
new {Population = 4000}
};
var averagePopulation = cities.Average(c => c.Population);
Console.WriteLine(averagePopulation);
// 2333,33
This method calculates the average of enumerable using delegated function.