At present, the yield of short-term Treasury bonds is 5%. Assuming that the expected return rate required by the market of a portfolio with β coefficient of 1 is 12%, according to the CAPM model, the following questions are asked:

(1) What is the expected rate of return of market asset portfolio?

(2) What is the expected return rate of a stock with a beta coefficient of 0?

(3) Suppose an investor is considering buying a stock that is currently priced at $40 per share and expects to pay a dividend of $3 per share next year. The investor can sell the stock at $41 per share. If the stock's beta coefficient is 0.5, is the stock overvalued or undervalued?