"Lance Oliver Company Limited (LOCL) hold a diversified portfolio consisting of $20,000 investment in common stocks with a beta of 1.75 . Suppose you decide to invest in proven APO and TransJamiacan highway with purchases $4,000 and $2,000 respectively, with the sum of both stocks having a beta of 2.1. The new investments will add to your portfolio. Calculate the new portfolio's beta." please show step by step calculation