title: "cannot find symbol: method" but the method is declared
body: <p>In my driver program, this line gives me <code>cannot find symbol</code> error and I don't know why. The method is clearly defined in the <code>SavingsAccount</code> class, and I can refer to all other methods in my driver program but just not that one, I tried changing the type to <code>double</code>, and etc but still not working.</p>
  
  <pre><code>Account acct2 = new SavingsAccount (name);
  acct2.calculateBalance();
  </code></pre>
  
  <p><code>SavingsAccount</code> class inherits from <code>Account</code> class:</p>
  
  <pre><code>public class SavingsAccount extends Account
  {
      private final short minBalance = 0;
      private double overdraftFee;
      private double yearlyInterestRate = 0.02;
      private double interestAmount;
  
      public SavingsAccount (String name)
      {
          super(name);
      }
  
      public double withdraw (double amount)
      {
          if (accountBalance - amount &gt;= minBalance)
          {
              accountBalance -= amount;
              System.out.print ("Withdraw Successful");
          }
          else 
          {
              accountBalance -= amount;
              overdraftFee = accountBalance * (0.10);
              accountBalance += overdraftFee;
              System.out.print ("Withdraw Succesful, however overdraft fee of 10% has been applied to your account");
  
  
          }
  
          return accountBalance;
      }
  
  // ----------------- this is the method I try to invoke -----------------------------
      public void calculateBalance ()
      {
          interestAmount = (accountBalance * yearlyInterestRate);
          accountBalance += interestAmount;
      }
  // ----------------------------------------------------------------------------------
  
      public String toString()
      {
          return super.toString() + " Interest Received: " + interestAmount;
      }
  
  
  }
  </code></pre>
  
  <p>Account class, if needed</p>
  
  <pre><code>import java.util.Random;
  import java.text.NumberFormat;
  
  public abstract class Account
  {
      protected double accountBalance;
      protected long accountNumber;
      protected String accountHolder;
      public Account (String name)
      {
          accountHolder = name;
          accountBalance = 0;
          Random accountNo = new Random();
          accountNumber  = accountNo.nextInt(100000);
      }
  
      public double deposit (double amount)
      {
          accountBalance += amount;
  
          return accountBalance;
      }
  
      public String toString()
      {
          NumberFormat accountBal = NumberFormat.getCurrencyInstance();
          return "Account Balance: " + accountBal.format(accountBalance) + "\nAccount Number: " + accountNumber;
      }
  
      public String getAccountHolder()
      {
          return accountHolder;
      }
  
      public double getAccountBalance()
      {
          return accountBalance;
      }
  
      public abstract double withdraw (double amount);
  
  }
  </code></pre>