Un ejercicio de cálculo básico en leguaje Java

public class ProvaReals{
public static void main (String args[] ){
float increment_percentual;
double q_final,q_inicial,increment;

q_final=4E+0D;
q_inicial=1.2E+0D;
increment=q_final-q_inicial;
increment_percentual = (float) (increment*100/q_inicial);

System.out.println("Q_f="+q_final);
System.out.println("Q_i="+q_inicial);
System.out.println("increment="+increment);
System.out.println("increment percentual="+increment_percentual+" %");
}
}