please show work and formulas on excel for all questions XYZ Co has 1500 units of bonds outstanding. Each unit has $100 face value. 8% coupon rate with semi annual payments, and 15 years to maturity. The risk free rate is 3%, default risk premium for its bond is 2%, maturity risk premium for 15 year maturity is 1.5%, XYZ has a tax rate of 20%. 1. a. Determine the required rate of return for its bonds, b. the amount of tax savings, c. the after tax cost of debt. 2. Determine a. value per unit of bond, B. determine total market value of all bonds outstanding. 3. If risk free rate goes up from 3% to 4% due to inflation, a. what is the new value of each unit of bond? b. what is the rate of change in the value of bond? c. what is the duration of the bond?