Java Programming

I have been working for 5 days on my calcluator program. Below is the problem presented:

Write the program in Java (without a graphical user interface) and have it calculate the payment amount for 3 mortgage loans:

- 7 year at 5.35%
- 15 year at 5.5%
- 30 year at 5.75%

Use an array for the different loans. Display the mortgage payment amount for each selected loan, which is picked at the run time of the program.
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Below is my program. Everything runs just fine. I started out just doing a menu to make sure it was presented properly, then I created the arrays and when I ran that, I got three different lines (corect results) from calculating each year with it's respective rate.

What is happening now, is that I am gettting the same result no matter whether I pick 1, 2 or 3 from the menu and if I choose 4, it just returns the menu. Everything else seems to be working. Could someone please take a look and tell me if I have left something out.... It would be most appreciated.

Code is below
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/**
* File name: Menu_Driven_Mortgage_Calculator.java
*
* Mortgage Calculator for Week 4
*
* Sandra Manchor
* version 4.00 June 16, 2008

*/

//Import Files

import java.math.*; //*loan calculator
import java.text.NumberFormat; //for currency format
import java.util.*; //for Scanner

class Menu_Driven_Mortgage_Calculator
{
public static void main(String[] arguments)
{
double amount = 200000;
int[] term = {7, 15, 30};
double[] rate = {5.35, 5.5, 5.75};


java.text.DecimalFormat dfm = new java.text.DecimalFormat(",###.00");

for (int i = 0; i < term.length; i++)
{
double payment = (amount*(rate/100/12))/(1-(Math.pow(1/(1+(rate[i]/100/12)),(term[i]*12))));
Scanner sc = new Scanner(System.in); //reads value from the keyboard

int choice = 1;

// end if user picks 4 or with invalid entry, continue program otherwise
while ( choice != 4 )
{
do {
if (choice > 4 || choice <= 0)
System.out.println("\nPlease make the correct selection. \n");

ShowMenu();

try {
choice = sc.nextInt(); //read in a numeric value, a decimal or an integer
}
catch (InputMismatchException e){
System.out.println("\nInvalid Entry! You should enter an integer from 1 to 4.");
System.out.println("The program has now ended.\n");
System.exit(1);
}
} while ( choice < 0 || choice > 4 );

if ( choice != 4 )
switch (choice) { // branch to an appropriate selection
case 1:
System.out.print("You have selected #1. \nFor a " + term[i] + " year mortgage at a rate of "+ rate[i]);
System.out.println(", the monthly payment will be $" + dfm.format(payment));
break;
case 2:
System.out.print("You have selected #2. \nFor a " + term[i] + " year mortgage at a rate of "+ rate[i]);
System.out.println(", the monthly payment will be $" + dfm.format(payment));
break;
case 3:
System.out.print("You have selected #3. \nFor a " + term[i] + " year mortgage at a rate of "+ rate[i]);
System.out.println(", the monthly payment will be $" + dfm.format(payment));
break;

}
else //choice 4 was selected
System.out.println("\n\n Thank you for using the Mortgage Calculator Program.\n");

} // end of while

} // end of main
}
private static void ShowMenu()
{
System.out.println(" Please make selection from the following:\n");
System.out.println(" 1 Calculate payment for 7 year term at 5.53%.");
System.out.println(" 2 Calculate payment for 15 year term at 5.5%.");
System.out.println(" 3 Calculate payment for 30 year term at 5.75%.");
System.out.println(" \n 4 End program \n");
System.out.print("\nEnter your choice: ");

} // end function ShowMenu

} // end of class