You are working as an intern at Coral Gables Products, a privately owned manufacturing company. You got into a discussion with the Chief Financial Officer (CFO) at Coral Gables about weighted average cost of capital calculations. She pointed out that, just as the beta
of the assets of a firm equals a weighted average of the betas for the individual assets (as shown below):

Bn Asset Portfolio = SUM_(t - 1, n) xiBi = x1B1 + x2B2 + ... + xnBn

The beta of the assets of a firm also equals a weighted average of the betas for the debt, preferred stock, and common stock of a firm:

Bn Asset Portfolio = SUM_(i = 1, n) xiBi = x_Debt * B_debt + x_ps * B_ps + x_cs * B_cs

a) Why must this be true? Please provide your explanation with appropriate exs.

b) Discuss your understanding of WACC and describe how the individual cost of each capital component (equity, preference and debt capital) can be find outd.