Your portfolio is invested 25% in McDonalds stock, 25% in Tiffany & Co. stock, 25% in an S&P 500 market index fund (like SPY), and 25% in a bank savings account. The CAPM betas for McDonalds and Tiffany are 0.67 and 1.88, respectively. Which is the best estimate for the beta of your entire portfolio?