please show the formula that you going to use

PORTFOLIO REQUIRED RETURN Suppose you are the money manager of a $4 million investment fund. The fund consists of four stocks with the following investments and betas: Stock Investment Beta 1.50 $ 400,000 B 600,000 (0.50) C 1,000,000 1.25 D 2,000,000 0.75 If the market's required rate of return is 14% and the risk-free rate is 6%, what is the fund's required rate of return