Please explain properly the (b) part of this question Thanks

The weighted average cost of capital (WACC) is a way of determining what interest ml 3 rm should use to evaluate its investments. TransCaIadonia is a pipeline company that delivers crude oil to reneries in Western Canada. TransCaladonia has the following capital structure: (return to base case after each part) Market Value Market Yield (cost of cap.) What is the weighted average cost of capital (WACC)? TransCaIadonia issued $500,000 in common stock - what is their new WACC? TransCaladonia issued some bonds to fund a new project. How much debt did they issue if their WACC dropped to 9% Trans Caladonia is negotiating a new bank loan to fund a new pipeline. The treasurer would like to get a loan of $600,000. What interest rate on the loan would drop the WACC to 8.75%