Your friend just announced she signed up for a free Spotify…

Your friend just announced she signed up for a free Spotify account. Happy with the service, but annoyed with the ads, she decided to add the paid subscription to her account that would eliminate the ad play a week later. Which one of the following models did Spotify utilize? 

You are asked in invest $ 1 mil, choosing one or more of the…

You are asked in invest $ 1 mil, choosing one or more of the following stocks. All stocks have the same expected return and standard deviation. The correlation matrix for the three stocks is given below Which of the three stocks, X, Y, and Z, should be included in the portfolio?