What should be the beta of a replacement stock if an investor wishes to achieve a portfolio beta of 1.2 by replacing stock C in the following equally…

What should be the beta of a replacement stock if an investor wishes to achieve a portfolio beta of 1.2 by replacing stock C in the following equally weighted portfolio: stock A = 0.9 beta; stock B = 1.1 beta; stock C = 1.35 beta?