Mkt RF: excess return on a market portfolio (return on market portfolio minus the risk-free rate); SMB: measures the size factor; HML: measures the value factor; RF: risk-free rate as the U.S. Treasury Bill rate; IBM: Continuously compounded returns on IBM stock (tech company); Coca cola: Continuously compounded returns on Coca-Cola (retail company); NRG: Continuously compounded returns on NRG (energy company); (a) If we wish to fit a CAPM model to three stocks, what is your expectation of the signs of and in the model for three stocks? Please explain your reasoning.