An investor with mean-variance preferences chooses to invest 70% of her wealth in a risky asset P with an expected rate of return of 15% and a standard deviation of 20%, and she puts 30% in a riskless Treasury bill that pays 5%. Let X denote the complete portfolio. The expected return of the portfolio C is and the standard deviation of the portfolio is .

Problem 3: access control pokeygram, a cutting-edge new email start-up, is setting up building access for its employees. there are two types of employees: managers and engineers, and there are three departments: security, networking, and human resoures. each employee works in a single department, and each department is housed on a different floor. managers are allowed access to any floor, while engineers are allowed access only to their own floor. there are three badge-operated elevators, each going up to only one distinct floor. every employee has one badge. pokeygram wants to use the best possible access control method in order to minimize delay for the elevators (a) access control matrix, 1. which of the following would you recommend that pokeygram use: (b) access control lists, or (c) capabilities? make sure to justify your answer. 2. what, if any, would be the benefits (and/or disadvantages) of using rbac (role-based access control) in this situation? keep your solution for this problem limited to 10-12 lines of text.