The following four macro-economic factors were identified regarding a stock As returns, the stock sensitivity to each factor and the related risk premium associated with each factor have been calculated as follows: Gross domestic product (GDP) growth=0.6 RP=4% Inflation rate= 0.8, RP=2% Platinum prices=-0.7, RP= 5% Standard and Poors 500 index return= 1.3 RP=9% The risk free rate is 3% Calculate the expected rate of return using the Arbitrage pricing theory formula.