Program:

The source code to print numbers whose value is less than average of all elements of integer array using LINQ in C# is given below. The given program is compiled and executed successfully on Microsoft Visual Studio.

using System;
using System.Linq;

class Number
{
    static void Main()
    {
        int[] intArr = {123,456,789,012,345,567,890};
        
        var nums = from num in intArr
                   let total = intArr.Sum()
                   let avg   = total/intArr.Length
                   where num < avg
                   select num;
       
        Console.WriteLine("Numbers are :");
        foreach (int n in nums)
        {
            Console.Write("{0} ",n);
        }
        Console.WriteLine();
    }
}

Output:

Numbers are :
123 12 345
Press any key to continue . . .

Explanation:

In the above program, we created a class Number that contains the Main() method.

int[] intArr = {123,456,789,012,345,567,890};

In the Main() method we created an integer array that contains multiple numbers.

var nums = from num in intArr
    let total = intArr.Sum()
    let avg   = total/intArr.Length
    where num < avg
    select num;

In the above code, we select numbers whose value is less than average of all elements in integer array using let statement of LINQ.

Console.WriteLine("Numbers are :");
foreach (int n in nums)
{
    Console.Write("{0} ",n);
}
Console.WriteLine();

In the above code, we printed the numbers selected from the LINQ query on the console screen.