Final answer:
To calculate the beta of a portfolio, we need the expected return of the market.
Step-by-step explanation:
The beta, β, of a portfolio can be calculated using the formula:
β = E(rp) / E(rm)
where E(rp) is the expected return of the portfolio and E(rm) is the expected return of the market. In this question, the student has given E(rp) = 13.1. To find the required beta, we need the expected return of the market, E(rm). Since the student has not provided that information, it is not possible to calculate the beta.