Calculate the weighted average cost of capital (WACC) for Company YZ, which has a cost of equity of 10%, a cost of debt of 5%, and a corporate tax rate of 30%. The company's target capital structure consists of 60% equity and 40% debt. Explain the weighted average cost of capital (WACC) as a measure of a company's cost of capital, indicating the average rate of return required by investors to finance its operations. Discuss the significance of WACC in investment analysis, capital budgeting decisions, and its implications for business valuation and cost of capital estimation.