On the basis of an analysis of past returns and of inflationary expectations, Martin feels that the expected return on stocks in general is 12 percent . The risk-free rate on short-term Treasury securities is now 7 percent. Martin is particularly interested in the return prospects for Amico Petroleum Corporation. Based on monthly data for the past five years,she has fitted a characteristic line to the responsibilities of excess returns of the stock to excess returns of the S&P 500Index and has found the slope of the line to be 1.67. If financial markets are believed to be efficient, return can he expect from investing in Amoco Petroleum Corporation?