A stock is expected to pay a dividend of $4 a share at the end of the year. The stock currently has a price of $40 a share, and the stocks dividend is expected to grow at a constant rate of g percent a year. The stock has a beta of 1.5. The market risk premium, kM kRF, is 8 percent and the risk-free rate is 5 percent. What is the constant dividend growth rate of the company?