5. For the Innis Investments example in Chapter 14, suppose that the investment returns are uncertain. Assume that each can be modeled as a lognormal distribution with a mean equal to the expected return in the example and a standard deviation equal to 10% of the mean.

a. For the optimal solution shown in Figure 14.9, what is the probability that the target return of 5% will be achieved?

b. What return will be achieved with a probability of 0.75 or more?