please 4-5 each thank you for your knowledge

Q1 Please turn to the section 65 (A single index of stock market) of Chapter 6 slides and answer the following questions: Why the market excess return ( Ritselis enough to predict the excess return of individual stock() in theory? Why this equation fails to predict returns in the real world see for example figure 6.12. the last page of the slides) and what could be the possible reasons? Reply Q2 Please turn to the Figure 6.11. (eg page 14 of the chapter 6 slides). This figure depicts the efficient frontier and optimal capital location line using real world data from six countries. Please try your best to answer this questions why the efficient frontier looks different between with short sells and no short ses For example, the blue colored frontier is seemingly larger than the black colored frontier. What could be the explanation to such difference Q1 Please turn to the section 65 (A single index of stock market) of Chapter 6 slides and answer the following questions: Why the market excess return ( Ritselis enough to predict the excess return of individual stock() in theory? Why this equation fails to predict returns in the real world see for example figure 6.12. the last page of the slides) and what could be the possible reasons? Reply Q2 Please turn to the Figure 6.11. (eg page 14 of the chapter 6 slides). This figure depicts the efficient frontier and optimal capital location line using real world data from six countries. Please try your best to answer this questions why the efficient frontier looks different between with short sells and no short ses For example, the blue colored frontier is seemingly larger than the black colored frontier. What could be the explanation to such difference