please show work in excel

Mullet Technologies is considering whether or not to refund a $75 million, 12% coupon, 30 -year bond issue that was sold 5 years ago. It is amortizing $5 million of flotation costs on the 12% bonds over the issue's 30-year life. Mullet's investment banks have indicated that the company could sell a new 25 -year issue at an interest rate of 10% in today's market. Neither they nor Mullet's management anticipate that interest rates will fall below 10% any time soon, but there is a chance that rates will increase. A call premium of 12% would be required to retire the old bonds, and flotation costs on the new issue would amount to $5 million. Mullet's marginal federal-plus-state tax rate is 40%. The new bonds would be issued 1 month before the old bonds are called, with the proceeds being invested in short-term government securities returning 6% annually during the interim period. a. Conduct a complete bond refunding analysis. What is the bond refunding's NPV? b. What factors would influence Mullet's decision to refund now rather than later