protected Account(Customer customer, decimal balance, decimal monthlyInterestRate)
 {
     this.Customer = customer;
     this.Balance = balance;
     this.MonthlyInterestRate = monthlyInterestRate;
 }
 public MortgageAccount(Customer customer, decimal balance, decimal interestRate)
     : base(customer, balance, interestRate)
 {
 }
 public DepositAccount(Customer customer, decimal balance, decimal interestRate)
     : base(customer, balance, interestRate)
 {
 }