4. A stock has a beta of 1.25, the expected return on the market is 15 percent, and the risk-free rate is 6 percent.

a. What must the expected return on this stock be?

c. Suppose the risk free rate falls to 4%. What is the expected return on this stock?

d. Suppose the expected return on the market is now 12 percent and the risk free rate is 6%. What is the expected return on his stock?