import cs1.Keyboard;
/**
   Calculate the sum, product and average of the first n reciprocals.
   @author Greg Vogl
   last modified 2003-09-22
*/
public class Firstnrecip
{
   /**
      Calculate the sum, product and average of the first n reciprocals.
      <br>input: integer n
      <br>output: sum, product, average
      @throws IOException to handle bad input
   */
   public static void main (String[] args) 
   {
      System.out.println("Calculate the sum, product and average of the first n integers.");

      // get input
      System.out.println("Type an integer and press Enter.");
      int n = Keyboard.readInt();

      // calculate statistics
      double sum = 0;
      double product = 1;
      for (int i=1; i<=n; i++)
      {
         sum += 1.0/i;
         product *= 1.0/i;
      }
      double average = sum / n;

      // output results
      System.out.println(sum + "\tSum");
      System.out.println(product + "\tProduct");
      System.out.println(average + "\tAverage");
   }
}