Assuming that you are using US equity, US fixed income, international equity, international fixed income, emerging market equity and developed market fixed income ETFs and that you are provided their quarterly returns and standard deviations, explain the necessary steps to build an optimal risky portfolio. Explain the importance of the variance-covariance matrix and the Sharpe Ratio in your response. After an optimal portfolio is constructed, what is the question that one must ask to fully implement the output (what did we talk about endlessly in class)?