Passing Values To Methods?

I'm supposed to write a program that reads in 20 numbers stores them into a one dimensional array and then create a method that will calculate the average of the numbers in a separate method.

I've written a for loop in the main method that will take in the numbers but now I need to know how I can pass those values to a method that will calculate the average.

public class ConstructorHomework {
private static double average; //Declaring the Global Variable
//This Method Calculates The Average
public void avg(int x){
average = x/20;

[Code] .....

This is the main method an it contains the for loop that will take in 20 numbers

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
final int size = 20;
double[] array = new double[size];
for (int i = 0; i < array.length; i++){
array[i] = input.nextDouble();
}
//

Here I was trying to create and object and use it to pass value to the method

ConstructorHomework a = new ConstructorHomework();
a.avg(); //Problem is that I don't know what to put in the brackets
a.showNum();
}
}