This week we are reviewing the Risk and the cost of Capital, I am having a difficult time and need assistance on the below.

What volatility measure can we use to evaluate and compare risk among different investment alternatives?

Why is the percentage return a more useful measure than the dollar return?

Describe how different allocations between the risk-free security and the market portfolio can achieve any level of market risk desired

Why is expected return considered "forward-looking"? What are the challenges for practitioners to utilize expected return?

Why do we use market-based weights instead of book-value-based weights when computing the WACC?