Answer:
7.5%
Step-by-step explanation:
Since the beta of this portfolio is 1, it means that it is perfectly synced with the market rate of return. We are told that the market rate of return is 7.5%, so that means that the expected rate of return of the portfolio should also be equal to 7.5%.
Beta measures the volatility of the portfolio or the stocks in relation to the market. If the stock is less volatile, the beta will be less than 1, if the stock is more volatile, the beta will be more than 1.