The risk-free rate and the expected market rate of return are 0.06 and 0.12, respectively. According to the capital asset pricing model (CAPM), the expected rate of return on security X with a beta of 1.2 is equal to:

13.2%

Explanation:

As per Capital Asset Pricing Model (CAPM),

Expected Rate Of Return =

wherein, = Risk free rate of return on treasury bonds

               B= Beta , which represents the degree of sensitivity of security return to the market return.

                = Return on market portfolio

Thus, Expected rate of return of security X = 6 + 1.2(12 - 6)

                                                                        = 13.2%

CAPM model is used for calculating expected rate of return. As per the model, the investors expect a risk premium represented by excess of rate of return of market portfolio over risk free rate , in addition for the risk free rate of return.

The risk premium serves as a compensation for investing in risky securities instead of risk free securities.