You have a four stock portfolio. 15% of your portfolio is invested in the a risky tech company with a beta of 1.8. You have 20% of your portfolio in an developing market stock with a beta of 1.6. You also decided to invest 30% of your stock in a petroleum company with a beta of 0.8. The remainder of your portfolio consists of retailer with a beta of 0.6. What is your portfolio beta?