I think I am on the right track... Please let me know if I screwed something up. I think I an done with Most of #1 but I am not sure which equation to use for Standard Deviation or #2 I will put down my work after the question. You have $10,000 saved up to invest for a year, and are considering stocks (S) and/or short term Treasury bills (T). The returns from both sources are judged uncertain, of course, as the following probability table indicates