Developed by Nobel Laureate Harry Markowitz, modern portfolio theory is a widely used investing model designed to help investors minimize riskwhile maximizing returns for their portfolio. The Markowitz efficient frontier is a set of portfolios with returns that are maximized for a given level of risk.

This question tests your understanding of efficient vs inefficient investments. Consider the following risky portfolios:

Portfolio. Expected Return. Standard Deviation

Q. 10.0%. 15.0%

R. 10.5%. 16.5%

S. 11.5%. 18.5%

Which of these portfolios cannot be on the Markowitz efficient frontier ofriskyassets (i.e.without the risk-free asset)? Explain briefly.