I have the following code for an assignment. Yes, this is for a class, so I don't want the answer given to me but I have searched the code over and I can't come up with anything. A nudge in the right direction would be great.

Code:
public class Loan {

	  public float P;
	  public float I;
	  public float Ia;
	  public int Nyr;
      public int Nprd;

	  public void setP() {
	  	P = 200000;
	  }
	  public void setI() {
	  	I = 5.75f;
	  	Ia = I/(12*100);
	  }
	  public void setN() {
	  	Nyr = 30;
	  	Nprd = Nyr*12;
	  }

	  public void CalcTbl() {
	  	float Pa;
	    int Pc; //current period num
	    float M;  //monthly payment
	    float Mi; //interest paid
	    float Mp; //principal paid
	  	Pa = P;
	  	Pc = 0;

	  	for(int Npa = Nprd; Npa = 0; Npa--) { //incompatible data types
	  		Pc ++;
	  		M = Pa * (Ia / (1- power(1+Ia,-1*Npa)));
	  		Mi = Pa * Ia;
	  		Mp = M - Mi;
	  		Pa = Pa - Mp;
	  		System.out.println("Current period " + Pc +
	  			" || Payment $" + M +
	  			" || Interest $" + Mi +
	  			" || Principal $" + Mp);
	  	}
	  }

	  public float power (float Base, double Pow) {
    	float Ans = Base;
    	for(double x = 2; x > Pow; x++) {
    		Ans = Ans * Base;}
    	return Ans;
    }
}

public class W2IA {
	public static void main(String[] args) {
    	Loan myLoan = new Loan();
    	myLoan.setP();
    	myLoan.setI();
    	myLoan.setN();

    	System.out.println("For a loan with:");
    	System.out.println("Principal amount of " + myLoan.P);
    	System.out.println("Interest of " + myLoan.I);
    	System.out.println("Number of periods (months) " + myLoan.Nprd);
		myLoan.CalcTbl();
    }
}
Thanks for the help.

-RT