the probability that he or she is accident prone? 3. A fair coin is tossed twice. What is the conditional probability that both tosses land on a. the first toss lands on heads? b. at least one toss lands on heads? A student is taking a one-hour-time-lin)it rnakeup examination. Suppose the probability that the student will finish the exam in less than x hours is x/2, for all OSxS1. Given that the student is still working after 0.75 hours, what is the conditional probability that the full hour is used? 5. Suppose we have an investnoent portfolio as follows: Bonds Stocks Connt)0dities Weight 0.6 0.2 0.2 2 10 15 Variance 0/6A2 6 25 40 Suppose the correlation between bonds and stocks return is 0.4, the correlation between bonds and conntnodities return is 0.2, and the correlation between stocks and commodities return is 0.35. a. What is the expected return and risk of this portfolio? b. What is the tnarginal contribution of commodities to the overall risk of this portfolio?