an arm loan with a teaser rate of 1.0% for the first loan year, an index of the one-year u.s. treasury, a margin of 2.5%, a periodic interest rate increase cap of 2.0% and a lifetime interest rate increase cap of 5.5% with annual adjustments, would have a maximum interest rate of what for the fourth loan year if the one-year u.s. treasury rate is 4.75% at the interest rate reset date just before the beginning of the fourth loan year?