consider a fa 15yr lpm 3/1 arm with no interest rate caps and no payment caps. the loan is for $600,000, with two point and other regulation-z fees of $15,000. the fixed period rate is 4% and the margin 1.5%. the underlying index at dates 0,1,2,3,4,5,6 years is 0.5%, 3%, 2%, 1%, 8%, 8%, 9%, respectively, and then stays at 9% until mortgage maturity. what is the apr?