//Confidence.java

import javax.swing.*;
import java.awt.*;
import java.text.*;
import java.util.*;

public class Confidence extends JApplet {
    public  void init () {

	JTextArea textarea = new JTextArea(22,100);
	textarea.setLineWrap( true );
	textarea.setFont( new Font("Courier",Font.BOLD,14) );
	JScrollPane scrollpane = new JScrollPane(textarea);
    	DecimalFormat d2 = new DecimalFormat ("0.00");
    	DecimalFormat d4 = new DecimalFormat ("0.0000");

	String input;
	int n;
	double pnum, p, q, sigmaPbar;
		
	input = JOptionPane.showInputDialog("Enter sample size n");//,
	n = Integer.parseInt(input);

	input = JOptionPane.showInputDialog("Enter integer number 'yes' or real number proportion 0<p<1");//,
	pnum = Double.parseDouble(input);
	
	if (pnum >= 1)
	    p = pnum / n;
	else
	    p = pnum;
	
	q = 1 - p;    
	sigmaPbar = Math.sqrt(p*q / n);

	textarea.append("n = "+n+"   p = "+d4.format(p)+"   sigma = "+d4.format(sigmaPbar)+"\n\n");
		
	textarea.append("68% CI: p ["+d4.format(p-sigmaPbar)+","+d4.format(p+sigmaPbar)+"]"+
		        "   ["+d2.format((p-sigmaPbar)*n)+","+d2.format((p+sigmaPbar)*n)+"]\n");
	textarea.append("90% CI: p ["+d4.format(p-1.647*sigmaPbar)+","+d4.format(p+1.647*sigmaPbar)+"]"+
		        "   ["+d2.format((p-1.647*sigmaPbar)*n)+","+d2.format((p+1.647*sigmaPbar)*n)+"]\n");
	textarea.append("95% CI: p ["+d4.format(p-2*sigmaPbar)+","+d4.format(p+2*sigmaPbar)+"]"+
		        "   ["+d2.format((p-2*sigmaPbar)*n)+","+d2.format((p+2*sigmaPbar)*n)+"]\n");
	textarea.append("98% CI: p ["+d4.format(p-2.32*sigmaPbar)+","+d4.format(p+2.32*sigmaPbar)+"]"+
		        "   ["+d2.format((p-2.32*sigmaPbar)*n)+","+d2.format((p+2.32*sigmaPbar)*n)+"]\n");
	textarea.append("99% CI: p ["+d4.format(p-3*sigmaPbar)+","+d4.format(p+3*sigmaPbar)+"]"+
		        "   ["+d2.format((p-3*sigmaPbar)*n)+","+d2.format((p+3*sigmaPbar)*n)+"]\n");
			

	JOptionPane.showMessageDialog(null, 
				      scrollpane,
				      "Confidence Intervals",
				      JOptionPane.PLAIN_MESSAGE);
    }
}