Assume the existence of a bank account class. define a derived class, savings account that contains two instance variables: the first a double, named interest rate, and the second an integer named interest type. the value of the interest type variable can be 1 for simple interest and 2 for compound interest. there is also a constructor that accepts two parameters: a double that is used to initialize the interest rate variable, and a string that you may assume will contain either "simple", or "compound", and which should be used to initialize the interest type variable appropriately. there should also be a pair of functions getinterest rate and getinterest type that return the values of the corresponding data members (as double and int respectively).