import java.io.*;

class IntervaloConfianza
{
	public static double diferencial(double alfa, double desv, int n)
	{
		DistNormal d = new DistNormal();
        return Math.abs(d.obtener_z(alfa / 2.0)) * desv / Math.sqrt(n);
	}		
	
	private static double redondear4d(double num)
    {
        double aux = num * 10000;
        int tmp = (int) aux;
    
        return (double) tmp / 10000;     
    }
	
	public static void main(String arg[]) throws IOException
	{
		BufferedReader in = new BufferedReader(new 
			InputStreamReader(System.in));

		String resp = "s";
		
		double media,desv,alfa;
		int tam;

		System.out.println("\n\tINTERVALO DE CONFIANZA PARA MEDIA Y DESV. ESTANDAR CONOCIDA");
		System.out.print("\t-----------------------------------------------------------");

		while(resp.charAt(0) == 's')
		{
			System.out.print("\n\n\tTamagno de la muestra : ");
			tam = Integer.parseInt(in.readLine());
			
			System.out.print("\tmedia muestral : ");
			media = Double.parseDouble(in.readLine());
			
			System.out.print("\tdesviacion estandar : ");
			desv = Double.parseDouble(in.readLine());
			
			System.out.print("\tPorcentaje de confianza % : ");
			alfa = Double.parseDouble(in.readLine());
			alfa /= 100.0;
			alfa = 1.0 - alfa;
			
			System.out.println("\n\t\tIntervalo de confianza");
			System.out.println("\t\t----------------------\n");
			
			System.out.println("\t\t" + redondear4d( media - diferencial(alfa,desv,tam) ) + " <= u <= " + 
				redondear4d(media + diferencial(alfa,desv,tam))  );
			
			
			System.out.print("\n\n\tDesea seguir (s/n) : ");
			resp = in.readLine();
		
			if (resp.charAt(0) == 's')
				System.out.println("\n\n\t------------------------------------");
		}
	}
}