Micron Technology's bonds currently sell for $1,280 and have a par value of $1,000. They pay a $105 annual coupon and have a 15-year maturity, but they can be called in 5 years at $1,100. What is their yield to call (YTC)? Your answer should be between 4.56 and 8.32, rounded to 2 decimal places, with no special characters