The risk-free rate is 5%. Tom's complete investment portfolio has an expected return of 18% and a standard deviation of return of 23%. Matthew's complete investment portfolio has an expected return of 15% and a standard deviation of return of 18%. Answer the following:

1. Calculate the degree of risk aversion for each investor.
2. Interpret the numbers you got from part a).
3. Between Tom and Matthew, who is more risk averse? Explain your answer.