Given that the risk-free rate is 5%, the expected return on the market portfolio is 20%, and the standard deviation of returns to the market portfolio is 20%, answer the following questions:

a. you have 100,000 to invest How should you allocate your wealth between the risk free asset and the market portfolio in order to have a 15% expected return?

b.What is the standard deviation of your portfolio in (a)? Please show step by step details and formulas.