Mart Corporation bonds have a $1,000 face value and will mature in four years. The bonds have a 7 percent coupon rate. Interest is paid annually, and the required rate of return is 6 percent for these bonds. a) What is the Macaulay duration of the Mart corporate bonds? b)lf interest rates increase 50 basis points, what will be the approximate price change in dollars ($) for the Mart bond? please answer in 1 hour