Write a program that inputs n positive integers into an array from the keyboard and prints the sum, average, and product of these numbers. Prompt the user for n . Use the method headers in your...

Write a program that inputsn positive integers into an array from the keyboard and prints the sum, average, and product of these numbers.  Prompt the user forn.  Use the method headers in your program:

               public static int sum( int[] a )
   public static double average( int[] a )
   public static int product( int[] a )