Part 1
​(Computing the standard deviation for a portfolio of two risky​ investments) Mary Guilott recently graduated from Nichols State University and is anxious to begin investing her meager savings as a way of applying what she has learned in business school.​ Specifically, she is evaluating an investment in a portfolio comprised of two​ firms' common stock. She has collected the following information about the common stock of Firm A and Firm​ B: