Use excel and show your excel workbook with the formulas in each cell. A bond has just been issued. The bond has an annual coupon rate of $7\%$ and coupons are paid annually. The bond has a face value of $$1,000$ and will mature in $9$ years. The bond's yield to maturity is $10\%.$

a$.$ Calculate the actual currency change in the bond's price as the yield to maturity changes from $10\%$ to $8\mathrm{.}5\%.$

b$.$ Use the bond's duration to calculate the bond's approximate currency price change as the yield to maturity changes from $10\%$ to $8\mathrm{.}5\%.$