Assume the yield curve is flat and the T-bill rate is 4%. The market return rate is 15%. The required rate of return for Stock A is 11.3%. An investor is forming a portfolio by investing $50,000 in stock A and $30,000 in stock B. Stock B has a beta of 0.90.What is the required rate of return on the investor's portfolio?

Stock	Required return	rRF	rM	Beta	Weight
A	11.3%
B

12.28% is the correct answer. Please show the solution. Thank you.