Can someone walk me through how to calculate the course average. The goal of this button is to calculate the course average for each of the courses, then print the average of each course and all the student information stored.

/* * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license * Click nbfs://nbhost/SystemFileSystem/Templates/GUIForms/JFrame.java to edit this template */ package pkg2d.assignment; import java.util.ArrayList; import javax.swing.JOptionPane; /** * * @author sprince */ public class StudentList extends javax.swing.JFrame { ArrayList studentGrades = new ArrayList(); /** * Creates new form StudentList */ public StudentList() { initComponents(); } /** * This method is called from within the constructor to initialize the form. * WARNING: Do NOT modify this code. The content of this method is always * regenerated by the Form Editor. */ @SuppressWarnings("unchecked") //  private void initComponents() { jSpinner1 = new javax.swing.JSpinner(); jScrollPane1 = new javax.swing.JScrollPane(); outputArea = new javax.swing.JTextArea(); titleLb = new javax.swing.JLabel(); firstNameLb = new javax.swing.JLabel(); lastNameLb = new javax.swing.JLabel(); testOneLb = new javax.swing.JLabel(); testTwoLb = new javax.swing.JLabel(); testThreeLb = new javax.swing.JLabel(); testFourLb = new javax.swing.JLabel(); firstInput = new javax.swing.JTextField(); lastInput = new javax.swing.JTextField(); oneField = new javax.swing.JTextField(); twoField = new javax.swing.JTextField(); threeField = new javax.swing.JTextField(); fourField = new javax.swing.JTextField(); addBtn = new javax.swing.JButton(); listBtn = new javax.swing.JButton(); studentAvgBtn = new javax.swing.JButton(); courseAvgBtn = new javax.swing.JButton(); exitBtn = new javax.swing.JButton(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); outputArea.setColumns(20); outputArea.setRows(5); jScrollPane1.setViewportView(outputArea); titleLb.setBackground(new java.awt.Color(240, 240, 250)); titleLb.setFont(new java.awt.Font("Consolas", 3, 36)); // NOI18N titleLb.setText("Student Grades"); firstNameLb.setFont(new java.awt.Font("Consolas", 2, 24)); // NOI18N firstNameLb.setText("First Name:"); lastNameLb.setFont(new java.awt.Font("Consolas", 2, 24)); // NOI18N lastNameLb.setText("Last Name:"); testOneLb.setFont(new java.awt.Font("Consolas", 2, 24)); // NOI18N testOneLb.setText("Test 1:"); testTwoLb.setFont(new java.awt.Font("Consolas", 2, 24)); // NOI18N testTwoLb.setText("Test 2:"); testThreeLb.setFont(new java.awt.Font("Consolas", 2, 24)); // NOI18N testThreeLb.setText("Test 3:"); testFourLb.setFont(new java.awt.Font("Consolas", 2, 24)); // NOI18N testFourLb.setText("Test 4:"); firstInput.setFont(new java.awt.Font("Consolas", 0, 18)); // NOI18N lastInput.setFont(new java.awt.Font("Consolas", 0, 18)); // NOI18N oneField.setFont(new java.awt.Font("Consolas", 0, 18)); // NOI18N twoField.setFont(new java.awt.Font("Consolas", 0, 18)); // NOI18N threeField.setFont(new java.awt.Font("Consolas", 0, 18)); // NOI18N fourField.setFont(new java.awt.Font("Consolas", 0, 18)); // NOI18N addBtn.setFont(new java.awt.Font("Consolas", 2, 18)); // NOI18N addBtn.setText("Add"); addBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { addBtnActionPerformed(evt); } }); listBtn.setFont(new java.awt.Font("Consolas", 2, 18)); // NOI18N listBtn.setText("List"); listBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { listBtnActionPerformed(evt); } }); studentAvgBtn.setFont(new java.awt.Font("Consolas", 2, 18)); // NOI18N studentAvgBtn.setText("Student Average"); studentAvgBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { studentAvgBtnActionPerformed(evt); } }); courseAvgBtn.setFont(new java.awt.Font("Consolas", 2, 18)); // NOI18N courseAvgBtn.setText("Course Average"); courseAvgBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { courseAvgBtnActionPerformed(evt); } }); exitBtn.setFont(new java.awt.Font("Consolas", 2, 18)); // NOI18N exitBtn.setText("Exit"); exitBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { exitBtnActionPerformed(evt); } }); javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane()); getContentPane().setLayout(layout); layout.setHorizontalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(27, 27, 27) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false) .addGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(testOneLb) .addComponent(testTwoLb) .addComponent(testThreeLb) .addComponent(testFourLb)) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(273, 273, 273) .addComponent(exitBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 114, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGroup(layout.createSequentialGroup() .addGap(271, 271, 271) .addComponent(courseAvgBtn, javax.swing.GroupLayout.PREFERRED_SIZE, 189, javax.swing.GroupLayout.PREFERRED_SIZE)))) .addGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING) .addComponent(oneField, javax.swing.GroupLayout.PREFERRED_SIZE, 169, javax.swing.GroupLayout.PREFERRED_SIZE) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false) .addGroup(layout.createSequentialGroup() .addComponent(lastNameLb) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(lastInput, javax.swing.GroupLayout.PREFERRED_SIZE, 169, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGroup(layout.createSequentialGroup() .addComponent(firstNameLb) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(firstInput, javax.swing.GroupLayout.PREFERRED_SIZE, 169, javax.swing.GroupLayout.PREFERRED_SIZE))) .addComponent(twoField, javax.swing.GroupLayout.PREFERRED_SIZE, 169, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(threeField, javax.swing.GroupLayout.PREFERRED_SIZE, 169, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(fourField, javax.swing.GroupLayout.PREFERRED_SIZE, 169, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGap(37, 37, 37) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(studentAvgBtn) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false) .addComponent(listBtn, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 114, Short.MAX_VALUE) .addComponent(addBtn, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))) .addComponent(jScrollPane1)) .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() .addGap(0, 165, Short.MAX_VALUE) .addComponent(titleLb) .addGap(165, 165, 165)) ); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() .addGap(15, 15, 15) .addComponent(titleLb) .addGap(18, 18, 18) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(firstNameLb) .addComponent(firstInput, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(addBtn)) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(lastNameLb) .addComponent(lastInput, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(listBtn)) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(testOneLb) .addComponent(oneField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(studentAvgBtn)) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(testTwoLb) .addComponent(twoField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(courseAvgBtn)) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(testThreeLb) .addComponent(threeField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(testFourLb) .addComponent(fourField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addComponent(exitBtn)) .addGap(18, 18, 18) .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 186, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) ); pack(); }//  private void courseAvgBtnActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: //Will need to add begining of code outputArea.setText("First NametLast NametTest 1tTest 2tTest 3tTest 4tStudent AveragetCourse Average "); for(int row = 0; row  tempRow = studentGrades.get(row); outputArea.append(tempRow.get(0)+"t"); outputArea.append(tempRow.get(1)+"t"); outputArea.append(tempRow.get(2)+"t"); outputArea.append(tempRow.get(3)+"t"); outputArea.append(tempRow.get(4)+"t"); outputArea.append(tempRow.get(5)+"t"); outputArea.append(tempRow.get(6)+"t"); outputArea.append(tempRow.get(7)+"t"); } } private void addBtnActionPerformed(java.awt.event.ActionEvent evt) { String firstName = firstInput.getText(); String lastName = lastInput.getText(); String testOne = oneField.getText(); String testTwo = twoField.getText(); String testThree = threeField.getText(); String testFour = fourField.getText(); if (firstName.equals("")){ JOptionPane.showMessageDialog(rootPane, "No First Name Entered");} else if (lastName.equals("")){ JOptionPane.showMessageDialog(rootPane, "No Last Name Entered");} else if (testOne.equals("")){ JOptionPane.showMessageDialog(rootPane, "No First Test Grade Entered");} else if (testTwo.equals("")){ JOptionPane.showMessageDialog(rootPane, "No Second Test Grade Entered");} else if (testThree.equals("")){ JOptionPane.showMessageDialog(rootPane, "No Third Test Grade Entered");} else if (testFour.equals("")){ JOptionPane.showMessageDialog(rootPane, "No Fourth Test Grade Entered");} else{ ArrayList tempRow = new ArrayList(); tempRow.add(firstName); tempRow.add(lastName); tempRow.add(testOne); tempRow.add(testTwo); tempRow.add(testThree); tempRow.add(testFour); studentGrades.add(tempRow); outputArea.append("Added Successfully!");} } private void listBtnActionPerformed(java.awt.event.ActionEvent evt) { outputArea.setText("First NametLast NametTest 1tTest 2tTest 3tTest 4 "); for(int row = 0; row  tempRow = studentGrades.get(row); outputArea.append(tempRow.get(0)+"t"); outputArea.append(tempRow.get(1)+"t"); outputArea.append(tempRow.get(2)+"t"); outputArea.append(tempRow.get(3)+"t"); outputArea.append(tempRow.get(4)+"t"); outputArea.append(tempRow.get(5)+"t"); } } private void studentAvgBtnActionPerformed(java.awt.event.ActionEvent evt) { String firstName = firstInput.getText(); String lastName = lastInput.getText(); String testOne = oneField.getText(); String testTwo = twoField.getText(); String testThree = threeField.getText(); String testFour = fourField.getText(); if (firstName.equals("")){ JOptionPane.showMessageDialog(rootPane, "No First Name Entered");} else if (lastName.equals("")){ JOptionPane.showMessageDialog(rootPane, "No Last Name Entered");} else{ double avg = (Integer.parseInt(testOne)+Integer.parseInt(testTwo)+Integer.parseInt(testThree)+Integer.parseInt(testFour)) / 4.00 ; studentGrades.get(studentGrades.size()-1).add(avg+"");} outputArea.setText("First NametLast NametTest 1tTest 2tTest 3tTest 4tStudent Average "); for(int row = 0; row  tempRow = studentGrades.get(row); outputArea.append(tempRow.get(0)+"t"); outputArea.append(tempRow.get(1)+"t"); outputArea.append(tempRow.get(2)+"t"); outputArea.append(tempRow.get(3)+"t"); outputArea.append(tempRow.get(4)+"t"); outputArea.append(tempRow.get(5)+"t"); outputArea.append(tempRow.get(6)+"t"); } } private void exitBtnActionPerformed(java.awt.event.ActionEvent evt) { System.exit(0); } /** * @param args the command line arguments */ public static void main(String args[]) { /* Set the Nimbus look and feel */ // /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html */ try { for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) { if ("Nimbus".equals(info.getName())) { javax.swing.UIManager.setLookAndFeel(info.getClassName()); break; } } } catch (ClassNotFoundException ex) { java.util.logging.Logger.getLogger(StudentList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (InstantiationException ex) { java.util.logging.Logger.getLogger(StudentList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (IllegalAccessException ex) { java.util.logging.Logger.getLogger(StudentList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (javax.swing.UnsupportedLookAndFeelException ex) { java.util.logging.Logger.getLogger(StudentList.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } // /* Create and display the form */ java.awt.EventQueue.invokeLater(new Runnable() { public void run() { new StudentList().setVisible(true); } }); } // Variables declaration - do not modify private javax.swing.JButton addBtn; private javax.swing.JButton courseAvgBtn; private javax.swing.JButton exitBtn; private javax.swing.JTextField firstInput; private javax.swing.JLabel firstNameLb; private javax.swing.JTextField fourField; private javax.swing.JScrollPane jScrollPane1; private javax.swing.JSpinner jSpinner1; private javax.swing.JTextField lastInput; private javax.swing.JLabel lastNameLb; private javax.swing.JButton listBtn; private javax.swing.JTextField oneField; private javax.swing.JTextArea outputArea; private javax.swing.JButton studentAvgBtn; private javax.swing.JLabel testFourLb; private javax.swing.JLabel testOneLb; private javax.swing.JLabel testThreeLb; private javax.swing.JLabel testTwoLb; private javax.swing.JTextField threeField; private javax.swing.JLabel titleLb; private javax.swing.JTextField twoField; // End of variables declaration }