Final answer:
The required rate of return on a security with a beta of 1.28 can be calculated using the CAPM formula. The required rate of return is 12.2%. If the security is expected to return 12%, it is not overpriced or underpriced.
Step-by-step explanation:
The required rate of return on a security can be calculated using the Capital Asset Pricing Model (CAPM) formula:
Required Rate of Return = Risk-Free Rate + Beta * (Expected Rate of Return on the Market Portfolio - Risk-Free Rate)
Given that the risk-free rate is 4%, the expected rate of return on the market portfolio is 9%, and the beta of the security is 1.28, we can plug in these values into the formula:
Required Rate of Return = 4% + 1.28 * (9% - 4%) = 12.2%
Therefore, the required rate of return on the security with a beta of 1.28 is 12.2%.
If the security is expected to return 12%, it is neither overpriced nor underpriced. The expected rate of return on the security matches the required rate of return, indicating that it is priced correctly according to its risk level.