After just trying to compile what I coded, I made what I hope are appropiate changes. . and so now my program looks like . .

import java.io.*;
import java.util.*;
import javax.swing.JOptionPane;

public class PropertyTax
{
public static void main(String [] args)
throws FileNotFoundException
{
String inputAssessedValueString;
double inputAssessedValue;
double taxableAmount;
double taxRate_hundreds;
double finalPropertyTax;

inputAssessedValueString = JOptionPane.showInputDialog
("Enter assessed value");

inputAssessedValue = Double.parseDouble(inputAssessedValueString);

taxableAmount = 0.92 * inputAssessedValue;
taxRate_hundreds = taxableAmount / 100;
finalPropertyTax = taxRate_hundreds * 1.05;

JOptionPane.showMessageDialog(null,
String.format("The Assessed Value equals $ %.2f%n",inputAssessedValue)
+ String.format("Taxable Amount equals $ %.2f%n", taxableAmount)
+ String.format("Tax Rate each $ 100.00: $ 1.05")
+ String.format("Property Tax equals %.2f%n", finalPropertyTax),
"Property Tax Calculation",
JOptionPane.INFORMATION_MESSAGE);

PrintWriter outFile = new PrintWriter("a:\\proptax.txt");

outFile.close();
}
}