<p>//This Java Program determines the weighted average of four test scores. P1 import javax.swing.*; import java.awt.*; import java.awt.event.*; import java.text.DecimalFormat; public class Ch6_PrExercise1 extends JFrame{ private JLabel blankoneL, blanktwoL, blankthreeL, scoreL, weightL, oneL, twoL, threeL,fourL,averageL; private JTextField oneTF, twoTF, threeTF, fourTF,woneTF, wtwoTF, wthreeTF, wfourTF, averageTF; private JButton calculateB, exitB; private CalculateButtonHandler cbHandler; private ExitButtonHandler ebHandler; private static final int WIDTH = 600; private static final int HEIGHT = 400; public Ch6_PrExercise1() { // Create eight labels blankoneL = new JLabel(""); blanktwoL = new JLabel(""); blankthreeL = new JLabel(""); scoreL = new JLabel("Score", SwingConstants.CENTER); weightL = new JLabel("Weight", SwingConstants.CENTER); oneL = new JLabel("Test one: ", SwingConstants.RIGHT); twoL = new JLabel("Test two: ", SwingConstants.RIGHT); threeL = new JLabel("Test three: ", SwingConstants.RIGHT); fourL = new JLabel("Test four: ", SwingConstants.RIGHT); averageL = new JLabel("Average score: ", SwingConstants.RIGHT); //Create four textfields oneTF = new JTextField(5); twoTF = new JTextField(5); threeTF = new JTextField(5); fourTF = new JTextField(5); woneTF = new JTextField(5); wtwoTF = new JTextField(5); wthreeTF = new JTextField(5); wfourTF = new JTextField(5); averageTF = new JTextField(5); //create Calculate Button</p><p>Chap6ProgEx6_1_Pg1 calculateB = new JButton("Calculate"); cbHandler = new CalculateButtonHandler(); calculateB.addActionListener(cbHandler); //Create Exit Button exitB = new JButton("Exit"); ebHandler = new ExitButtonHandler(); exitB.addActionListener(ebHandler); //Set the title of the window setTitle("Weighted Average Computation"); //Get the container Container pane = getContentPane(); //Set the layout pane.setLayout(new GridLayout(7,3)); //Place the components in the pane pane.add(blankoneL); pane.add(scoreL); pane.add(weightL); //first row pane.add(oneL); pane.add(oneTF); pane.add(woneTF); //second row pane.add(twoL); pane.add(twoTF); pane.add(wtwoTF);//third row pane.add(threeL); pane.add(threeTF); pane.add(wthreeTF); //fourth row pane.add(fourL); pane.add(fourTF); pane.add(wfourTF);//fifth row pane.add(averageL); pane.add(averageTF); pane.add(blanktwoL); //sixth row pane.add(calculateB); pane.add(blankthreeL); pane.add(exitB); //seventh row //set the size of the window and display it setSize(WIDTH, HEIGHT);</p><p>Chap6ProgEx6_1_Pg2 setVisible(true); setDefaultCloseOperation(EXIT_ON_CLOSE); } private class CalculateButtonHandler implements ActionListener{ public void actionPerformed(ActionEvent e){ double one, wone, two, wtwo, three, wthree, four, wfour, ave; DecimalFormat twoDigits = new DecimalFormat("0.00"); one = Double.parseDouble(oneTF.getText()); wone = Double.parseDouble(woneTF.getText()); two = Double.parseDouble(twoTF.getText()); wtwo = Double.parseDouble(wtwoTF.getText()); three = Double.parseDouble(threeTF.getText()); wthree = Double.parseDouble(wthreeTF.getText()); four = Double.parseDouble(fourTF.getText()); wfour = Double.parseDouble(wfourTF.getText()); ave = (one * wone + two * wtwo + three * wthree + four * wfour)/(wone+wtwo+wthree+wfour); averageTF.setText(""+ twoDigits.format(ave)); } } private class ExitButtonHandler implements ActionListener{ public void actionPerformed(ActionEvent e){ System.exit(0); } } public static void main(String[] args) { Ch6_PrExercise1 wAveObject = new Ch6_PrExercise1(); } }</p><p>Chap6ProgEx6_1_Pg3</p>