help please

What return would an investor with a risk aversion of A=4 require on an investment with a standard deviation of 0.51, if the riskfree rate is 0.012 ? What utility does an investor with a risk aversion of A=5.5 receive from a portfolio with an expected return of 0.16 and a standard deviation of 0.84 ? Question 5 If there is a risky asset with a standard deviation of 0.49, what would be the standard deviation of a portfolio with a weight of 0.3 on the risky asset, and a weight of 1-0.3 on the risk free asset