5. The risk-free rate (per annum with semi-annual compounding) is 5%. You have a portfolio worth 10000 dollars today. Let X be the return of your portfolio in 6 months. (The return means the gain, or increase, 9.6. PROBLEMS 177 if positive, in your portfolio value. If the return is negative it means your portfolio value decreased.) Suppose the p.d.f. of X is given by x + 50 fx (x) = if - 50