public static double getPrimeIntRate() {
        Scanner sc = new Scanner(System.in);
        double primeIntRate;
        
        // asks user to enter prime interest rate, then validates input
        try {
            System.out.print(" Prime interest rate (%): ");
            primeIntRate = sc.nextDouble();
            
            if (primeIntRate <= 0) {
                throw (new InputMismatchException("Interest rate must " +
                        "not be zero or lesser."));
            }
            
            return primeIntRate;
        } catch (InputMismatchException e) {
            getExceptionMessage("interest rate", e);
            return getPrimeIntRate();
        }
    }