The Treasury bill rate is 6%, and the expected return on the market portfolio is 10%. According to the capital asset pricing model:

a. What is the risk premium on the market? b. What is the required return on an investment with a beta of 1.5? (Do not round intermediate calculations. Enter your answer as a percent rounded to 1 decimal place.) c. If an investment with a beta of 0.7 offers an expected return of 8.5%, does it have a positive or negative NPV? d. If the market expects a return of 10.8% from stock X, what is its beta? (Do not round intermediate calculations. Round your answer to 2 decimal places.)