4. Your uncle has had a standard 30-year FRM with a 5% interest rate for 2 years (24 months); the original principal was $200,000. One day he calls you up, very excitedly: "My bank offered to refinance my mortgage to a new 30-year ARM with a 2.5% interest rate. This is awesome since the interest rate is cut in half, my monthly payment will also be cut in half!\" A. Is the second part of his statement correct? By how much does his payment go down? In addition to showing a calculation, please try to briefly explain intuitively what is going on